Democrats won a supermajority in the California State Senate in the 2018 elections, controlling 29 seats to Republicans' 11. A party needed to control 27 seats to hold a two-thirds supermajority.

A total of 20 seats out of the chamber's 40 seats were up for election in 2018. Heading into the election, Democrats controlled 26 seats and Republicans controlled 14.

Democrats maintained their trifecta in California by holding the state Assembly, the state Senate, and the governor's office.

California state senators serve staggered, four-year terms and half of the Senate is up for election every two years.

The California State Senate was one of 87 state legislative chambers holding elections in 2018. There are 99 chambers throughout the country. In 2017, three chambers in Virginia and New Jersey were up for election. In 2016, 86 out of 99 legislative chambers held elections. Prior to 2018, the California State Senate last held elections in 2016.

Post-election analysis

The Democratic Party attained supermajority status in both chambers of the California State Legislature in the 2018 election. Democrats in the California State Assembly already held a supermajority, but Democrats in the California State Senate did not previously hold the minimum 27 seats needed for a supermajority. In the state Senate, 20 out of 40 seats were up for election. Democrats increased their majority in the California State Senate from 26-14 to 29-11. Two Republican incumbents were defeated in the general election.

The California State Assembly held elections for all 80 seats. The Democratic supermajority in the State Assembly increased from 55-25 to 60-20. Three Republican incumbents were defeated in the general election.

National background

On November 6, 2018, 87 of the nation's 99 state legislative chambers held regularly scheduled elections for 6,073 of 7,383 total seats, meaning that nearly 82 percent of all state legislative seats were up for election.

• Entering the 2018 election, Democrats held 42.6 percent, Republicans held 56.8 percent, and independents and other parties held 0.6 percent of the seats up for regular election.
• Following the 2018 election, Democrats held 47.3 percent, Republicans held 52.3 percent, and independents and other parties held 0.4 percent of the seats up for regular election.
• A total of 469 incumbents were defeated over the course of the election cycle, with roughly one-third of them defeated in the primary.

Want more information?

• Incumbents defeated in 2018's state legislative elections
• 2018 election analysis: Partisan balance of state legislative chambers
• 2018 election analysis: Number of state legislators by party
• 2018 election analysis: State legislative supermajorities

Candidates

General election candidates

California State Senate elections, 2018

Incumbents are marked with an (i) after their name.

Office	Democrat	Republican	Other
District 2	Veronica Jacobi Mike McGuire (i)
District 4	Phillip Kim	Jim Nielsen (i)
District 6	Richard Pan (i)		Eric Frame (Independent)
District 8	Paulina Miranda	Andreas Borgeas
District 10	Bob Wieckowski (i)	Victor San Vicente
District 12	Anna Caballero	Rob Poythress
District 14	Melissa Hurtado	Andy Vidak (i)
District 16	Ruth Musser-Lopez	Shannon Grove
District 18	Robert Hertzberg (i)	Rudy Melendez
District 20	Connie Leyva (i)	Matthew Munson
District 22	Mike Eng Susan Rubio
District 24	Maria Elena Durazo Peter Choi
District 26	Ben Allen (i)		Baron Bruno (Independent)
District 28	Joy Silver	Jeff Stone (i)
District 30	Holly Mitchell (i)
District 32	Bob Archuleta	Rita Topalian
District 34	Tom Umberg	Janet Nguyen (i)
District 36	Marggie Castellano	Patricia Bates (i)
District 38	Jeff Griffith	Brian Jones
District 40	Ben Hueso (i)	Luis R. Vargas

Primary election candidates

The candidate list below is based on a list provided by the California Secretary of State website on March 29, 2018. The filing deadline for the June primary was on March 9, 2018. (I) denotes an incumbent.

2018 California State Senate primary candidates
District	Democrat	Republican	Other
2	Mike McGuire: 160,516 (I) Veronica Jacobi: 49,852	No candidate
4	Phillip Kim: 23,196 Michael Worley: 20,958	Jim Nielsen: 67,849 (I)
6	Richard Pan: 40,146 (I) Jacob Mason: 6,414	No candidate	Eric Frame: 9,043 (Ind.) Janine DeRose: 6,320 (L)
8	Paulina Miranda: 24,854 Tom Pratt: 18,178	Andreas Borgeas: 68,989	Mark Belden: 4,209 (Ind.)
10	Bob Wieckowski: 53,362 (I)	Victor San Vicente: 19,430	Ali Sarsak: 3,263 (L)
12	Anna Caballero: 24,902 Daniel Parra: 5,093	Rob Poythress: 16,239 Johnny Tacherra: 14,314
14	Melissa Hurtado: 9,787 Ruben Macareno: 3,319 Abigail Solis: 6,016	Andy Vidak: 22,948 (I)
16	Ruth Musser-Lopez: 28,552	Shannon Grove: 60,735 Gregory Tatum: 12,105
18	Robert Hertzberg: 46,025 (I) Roger James Sayegh: 7,584	Rudy Melendez: 8,510 Brandon Saario: 8,064
20	Connie M. Leyva: 25,296 (I) Paul Avila: 9,844	Matthew Munson: 19,486
22	Mike Eng: 24,086 Monica Garcia: 11,452 Susan Rubio: 14,923 Ruben Sierra: 4,287	No candidate
24	Peter Choi: 17,218 Maria Elena Durazo: 40,360	No candidate
26	Ben Allen: 88,635 (I)	No candidate	Baron Bruno: 15,582 (Ind.) Mark Matthew Herd: 13,441 (L)
28	Anna Nevenic: 8,470 Joy Silver: 31,760	Jeff Stone: 51,026 (I)
30	Holly Mitchell: 57,484 (I)	No candidate
32	Bob Archuleta: 14,564 Rudy Bermudez: 3,863 David Castellanos: 1,060 Vanessa Delgado: 12,745 Tony Mendoza: 8,130 Vivian Romero: 3,609 Vicky Santana: 5,440 Ali Taj: 4,162	Ion Sarega: 8,015 Rita Topalian: 20,077
34	Akash Hawkins: 4,832 Jestin Samson: 7,249 Tom Umberg: 22,219	Janet Nguyen: 49,501 (I)
36	Marggie Castellano: 63,026	Patricia C. Bates: 75,990 (I)
38	Jeff Griffith: 46,968	Brian Jones: 71,230	Antonio Salguero: 3,082 (L)
40	Ben Hueso: 40,626 (I)	Luis R. Vargas: 28,917
Notes	• An (I) denotes an incumbent.
	Elections Project.

Margins of victory

A margin of victory (MOV) analysis for the 2018 California State Senate races is presented in this section. MOV represents the percentage of total votes that separated the winner and the second-place finisher. For example, if the winner of a race received 47 percent of the vote and the second-place finisher received 45 percent of the vote, the MOV is 2 percent.

The table below presents the following figures for each party:

• Elections won
• Elections won by less than 10 percentage points
• Elections won without opposition
• Average margin of victory

California State Senate: 2018 Margin of Victory Analysis
Party	Elections won	Elections won by less than 10%	Unopposed elections	Average margin of victory
Democratic	14	3	1	30.7%
Republican	6	3	0	12.4%
Other	0	0	0	N/A
Total	20	6	1	21.6%

The margin of victory in each race is presented below. The list is sorted from the closest MOV to the largest (including unopposed races).

California State Senate: 2018 Margin of Victory by District

District	Winning Party	Losing Party	Margin of Victory
California State Senate District 34	Democratic	Republican	1.2%
California State Senate District 36	Republican	Democratic	3.1%
California State Senate District 28	Republican	Democratic	3.2%
California State Senate District 22	Democratic	Democratic	4.6%
California State Senate District 38	Republican	Democratic	6.0%
California State Senate District 12	Democratic	Republican	8.7%
California State Senate District 14	Democratic	Republican	11.6%
California State Senate District 4	Republican	Democratic	14.3%
California State Senate District 8	Republican	Democratic	19.2%
California State Senate District 16	Republican	Democratic	28.4%
California State Senate District 40	Democratic	Republican	31.7%
California State Senate District 24	Democratic	Democratic	33.7%
California State Senate District 32	Democratic	Republican	33.8%
California State Senate District 2	Democratic	Democratic	34.4%
California State Senate District 20	Democratic	Republican	38.9%
California State Senate District 6	Democratic	Independent	39.1%
California State Senate District 10	Democratic	Republican	51.2%
California State Senate District 26	Democratic	Independent	54.5%
California State Senate District 18	Democratic	Republican	56.2%
California State Senate District 30	Democratic	None	Unopposed

Seats flipped

The below map displays each seat in the California State Senate which changed partisan hands as a result of the 2018 elections, shaded according to the partisan affiliation of the winner in 2018. Hover over a shaded district for more information.

State legislative seats flipped in 2018, California State Senate

District	Incumbent	2018 winner	Direction of flip
California State Senate District 12	Anthony Cannella	Anna Caballero	R to D
California State Senate District 14	Andy Vidak	Melissa Hurtado	R to D
California State Senate District 34	Janet Nguyen	Tom Umberg	R to D

Incumbents retiring

Eight incumbents did not run for re-election in 2018. Those incumbents were:

Name	Party	Current Office
Tom Berryhill	Republican	Senate District 8
Anthony Cannella	Republican	Senate District 12
Jean Fuller	Republican	Senate District 16
Edward Hernandez	Democratic	Senate District 22
Kevin de León	Democratic	Senate District 24
Ling Ling Chang	Republican	Senate District 29
Joel Anderson	Republican	Senate District 38

Process to become a candidate

See statutes: Section 8020-8028 and Section 8100-8107 of the California Elections Code

Before accepting or spending money related to campaigning for office, a candidate for state office must file a candidate intention statement with the California Secretary of State. Note that this requirement does not apply to candidates for congressional office; federal campaign finance requirements apply to candidates for federal office. Candidates may qualify to run for office either by paying a filing fee or by submitting a petition in lieu of the filing fee.

In addition to the candidate intention statement, a candidate is required to file nomination forms with his or her home county. These forms become available as early as the 113th day prior to the primary election and must be filed no later than the 88th day prior to the primary election.

Nomination forms include a statement of economic interests, a declaration of candidacy, and nomination papers. Nomination papers require a certain number of signatures from registered voters. If a candidate qualifies by submitting an in-lieu-of-filing-fee petition, the signatures on that petition will be counted towards the requirement for the nomination paper. Registered voters may sign both the in-lieu-of-filing-fee petition and the nomination paper, unless the candidate is using the signatures on the in-lieu-of-filing-fee petition to count toward the nomination paper requirement. If that is the case, a registered voter can sign only one of the documents.

The number of signatures required for nomination papers are as follows:

• 65-100 for candidates seeking the office of United States Senator or a state executive office
• 40-60 for candidates seeking the office of United States Representative, state senator, or state assembly member

If an individual is running as a write-in candidate, the only nomination forms required are the nomination papers and a statement of write-in candidacy. These forms should be filed in the candidate's home county.

Qualifying by payment of fee

The filing fee for a candidate seeking a seat in the United States Senate or a state executive office (e.g., governor or treasurer) is 2 percent of the first year's salary for that office. The filing fee for a candidate seeking the office of United States Representative, state senator, or state assembly member is 1 percent of the first year's salary for that office. The fee is paid to the California Secretary of State through the candidate's home county election office.

Qualifying by petition in lieu of filing fee

Instead of paying a filing fee, a candidate may submit a petition. Signatures may be collected to cover all or any prorated portion of the filing fee.

A candidate seeking the office of state assembly member must file signatures from 1,000 registered voters. Those seeking the office of state senator or United States Representative must file 2,000 signatures, and those seeking statewide office must file 7,000 signatures.

If the number of registered voters in the district in which the candidate seeks nomination is less than 2,000, a candidate may submit a petition containing four signatures for each dollar of the filing fee, or 20 percent of the total number of registered voters in the district in which he or she seeks nomination, whichever is less.

Completed petitions must be submitted 15 days before the end of the qualifying period to the counties in which the signers reside.

Qualifications

According to Article IV of the California Constitution, the candidate must be a United States Citizen, a resident of California for three years, a resident of the legislative district for one year and a registered voter in that district by the time nomination papers are filed.

Salaries and per diem

When sworn in

California legislators assume office the first Monday in the December following their election.

California political history

Party control

2018

In the 2018 elections, Democrats increased their majority in the California State Senate from 26-14 to 29-11.

2016

In 2016, Democrats increased their majority in the California State Senate from 26-13 to 27-13, gaining a two-thirds supermajority in the chamber. In California, a two-thirds vote in each legislative chamber is required to increase taxes, certify proposed constitutional amendments for the ballot, enact laws immediately through an urgency clause, and override a gubernatorial veto.

Democrats also gained a 55-25 majority in the California State Assembly in 2016, giving Democrats a two-thirds supermajority in both chambers.

Trifectas

A state government trifecta is a term that describes single-party government, when one political party holds the governor's office and has majorities in both chambers of the legislature in a state government. Democrats gained a trifecta in California as a result of the 2010 election when they recaptured the governor's office. Democrats had trifectas from 1999 to 2003 and from 2011 to 2017.

Impact of term limits

The California State Senate has been a term-limited state Senate since California voters approved Proposition 140 in 1990. In 2012, California voters approved Proposition 28, which reduced the total number of years a politician can serve in the California State Legislature from 14 years to 12 years. It permits a politician to serve in either or both chambers of the legislature for a maximum of 12 years. The changes did not apply to any legislator who was already in office at the time that the initiative was approved; the rules governing the terms of those who are in the California State Legislature as of June 5, 2012, are calculated under the previous rules.

A total of 20 out of 40 seats in the California State Senate were up for election in 2018. In the 2018 elections, six senators were ineligible to run because of term limits. The following state senators were term-limited in 2018:

Democratic: (2)

• Edward Hernandez
• Kevin de León

Republicans (4):

• Tom Berryhill
• Anthony Cannella
• Jean Fuller
• Joel Anderson

Of the 87 state legislative chambers that held elections in 2018, 24 of them—12 senate chambers and 12 house chambers—included incumbents who were unable to run for re-election due to term limits. In the 24 chambers affected by term limits in 2018, 1,463 seats were up for election. The Nevada Senate, Arkansas House, and Arkansas Senate are impacted by term limits, but no incumbents were term-limited in 2018. There are 99 chambers throughout the country.

A total of 271 state legislators—96 state senators and 175 state representatives—were ineligible to run in the 2018 elections because of term limits. This represented 4 percent of the 6,066 total seats up for election in November 2018. Republicans had twice as many state legislators term-limited in 2018 than Democrats. A total of 86 Democrats were term-limited, while 177 Republicans were term-limited.

Wave election analysis

The term wave election is frequently used to describe an election cycle in which one party makes significant electoral gains. How many seats would Republicans have had to lose for the 2018 midterm election to be considered a wave election?

Woodrow Wilson's (D) second midterm in 1918 to Donald Trump's (R) first presidential election in 2016. We define wave elections as the 20 percent of elections in that period resulting in the greatest seat swings against the president's party.

Applying this definition to state legislative elections, we found that Republicans needed to lose 494 seats for 2018 to qualify as a wave election.

State legislative wave elections

Competitiveness

Results from 2016

Historical context

Uncontested elections: Uncontested elections have become a staple of state legislative elections. In 2014, 32.8 percent of Americans lived in states with an uncontested state senate election. Similarly, 40.4 percent of Americans lived in states with uncontested house elections. Primary elections were uncontested even more frequently, with 61 percent of people living in states with no contested primaries. Traditionally, Southern states have experienced more uncontested elections than the rest of the country, though this has begun to change in more recent elections. Uncontested elections often occur in locations that are so politically one-sided that the result of an election would be a foregone conclusion regardless of whether it was contested or not.

Open seats: In most cases, an incumbent will run for re-election, which decreases the number of open seats available. In 2014, 83 percent of the 6,057 seats up for election saw the incumbent running for re-election. The states that impose term limits on their legislatures typically see a higher percentage of open seats in a given year because a portion of incumbents in each election are forced to leave office. Overall, the number of open seats decreased from 2012 to 2014, dropping from 21.2 percent in 2012 to 17.0 percent in 2014.

Incumbent win rates:competitiveness analysis documented the high propensity for incumbents to win re-election in state legislative elections. In fact, since 1972, the win rate for incumbents has not dropped below 90 percent—with the exception of 1974, when 88 percent of incumbents were re-elected to their seats. The 1974 election, however, is unique in that it followed the Watergate scandal and gave Democrats the opportunity to sweep seats across the nation. Perhaps most importantly, the win rate for incumbents has generally increased over time. In 2014, 96.5 percent of incumbents were able to retain their seats. Common convention holds that incumbents are able to leverage their office to maintain their seat. However, the high incumbent win rate may actually be a result of incumbents being more likely to hold seats in districts that are considered safe for their party.

Marginal primaries: Often, competitiveness is measured by examining the rate of elections that have been won by amounts that are considered marginal (5 percent or less). During the 2014 election, 90.1 percent of primary and general election races were won by margins higher than 5 percent. Interestingly, it is usually the case that only one of the two races—primary or general—will be competitive at a time. This means that if a district's general election is competitive, typically one or more of the district's primaries were won by more than 5 percent. The reverse is also true: If a district sees a competitive primary, it is unlikely that the general election for that district will be won by less than 5 percent. Primaries often see very low voter turnout in comparison to general elections. In 2014, there were only 27 million voters for state legislative primaries, but approximately 107 million voters for the state legislative general elections.

Pivot Counties

There are no Pivot Counties in California. Pivot Counties are counties that voted for Barack Obama (D) in 2008 and 2012 and for Donald Trump (R) in 2016. Altogether, the nation had 206 Pivot Counties, with most being concentrated in upper midwestern and northeastern states.

In the 2016 presidential election, Hillary Clinton (D) won California with 61.7 percent of the vote. Donald Trump (R) received 31.6 percent. In presidential elections between 1900 and 2016, California voted Republican 53.33 percent of the time and Democratic 43.33 percent of the time. In the five presidential elections between 2000 and 2016, California voted Democratic all five times. In 2016, California had 55 electoral votes, which was the most of any state. The 55 electoral votes were 10.2 percent of all 538 available electoral votes and were 20.4 percent of the 270 electoral votes needed to win the election.

Presidential results by legislative district

The following table details results of the 2012 and 2016 presidential elections by state Senate districts in California. The "Obama," "Romney," "Clinton," and "Trump" columns describe the percent of the vote each presidential candidate received in the district. The "2012 Margin" and "2016 Margin" columns describe the margin of victory between the two presidential candidates in those years. The "Party Control" column notes which party held that seat heading into the 2018 general election. Data on the results of the 2012 and 2016 presidential elections broken down by state legislative districts was compiled by Daily Kos.

2016 Presidential Results by State Senate District