And with only two of the 53 Republican senators dissenting from the decision to move forward with filling the vacancy as soon as possible, McConnell and his members have made the calculated gamble that there is little downside for them politically to act on the seat this year. McConnell has “come up with a decision that has the most net gain,” said GOP Sen. Kevin Cramer, who won his North Dakota seat in 2018 after Brett Kavanaugh’s bitter confirmation fight.

“A Supreme Court debate right before an election is good for us,” said Senate Judiciary Chairman Lindsey Graham (R-S.C.), who is facing a surprisingly strong challenge from Democrat Jaime Harrison. “It’s a right-of-center nation, certainly in South Carolina it is. It’s an event that will matter in these races.”

The country is still battling the coronavirus with tens of millions unemployed, and the Senate has failed to pass a new stimulus bill. So it's an open question whether the Supreme Court fight will be the primary issue on the minds of independents and persuadable voters as they begin to cast votes this month.

But during their first weekly lunch since Ginsburg’s death, held at the National Republican Senatorial Committee on Tuesday, most incumbent senators said they believed the Supreme Court is likely to be the top issue in their races in November, according to an attendee.

Sen. Tom Cotton (R-Ark.) urged his colleagues not to buy Democrats’ threats of retaliation if the GOP confirms a new nominee, according to a source familiar with his remarks, and Republicans viewed a video of Democrats saying the court needs nine justices during the Garland fight.

The makeup of the federal judiciary and issues like abortion have animated evangelicals for decades, causing them to turn out in droves for Republicans up and down the ballot. But this year, Democrats will use the Supreme Court opening to galvanize their coalition, too.

The Trump administration’s lawsuit seeking to invalidate the Affordable Care Act will be among the high court’s first orders of business after the election. That means that 2020 — like the 2018 midterms, when Democrats won back the House majority — will be all about health care, said Sen. Chris Murphy (D-Conn.).

“Democrats sometimes have a hard time remembering that health care is the number one issue for voters, and it’s what won the House majority in 2018,” Murphy said. “This guarantees that the 2020 election is going to be all about health care and the repeal of the Affordable Care Act given that that’s the decision that will be most affected by a new justice on the Supreme Court.”

Yet Republicans say there’s no better way to bring out conservative voters than to remind them of the GOP’s herculean effort to shift the balance of the court over the past five years by blocking President Barack Obama’s vacancy in an election year — and filling another one for Trump four years later potentially just days before Election Day.

Sen. Steve Daines (R-Mont.), who is facing popular Democratic Gov. Steve Bullock this year, said the Supreme Court vacancy distills the race to “a very clear choice” for voters.

“It’s going to help. People are motivated,” added Sen. Joni Ernst (R-Iowa), who sits on the Senate Judiciary Committee and is facing a stiff challenge from Democrat Theresa Greenfield.

A quick confirmation vote may be an unpopular decision among the broader public: Fifty percent of those surveyed in a recent POLITICO/Morning Consult poll said the presidential election winner should pick Ginsburg’s successor, while 37 percent said Trump should fill the seat. New York Times polls in battleground states showed that voters prefer that Biden make a Supreme Court pick over Trump.

But Senate races are being fought largely in GOP-leaning territory and party officials think the vacancy may be a boon to many Republicans’ chances. The states with GOP incumbents facing potential danger include Colorado, Arizona, Maine, North Carolina, Iowa, Montana and Georgia.

Dan Eberhart, a GOP donor, said the vacancy “helps on the margins. But in some of these races that’s a big deal.”

“It helps candidates that were running behind Trump and hurts ones that were running better than Trump,” Eberhart said. “It hurts people like Cory Gardner and Susan Collins. I think it helps people like [Thom] Tillis, [Martha] McSally and Ernst.”

Gardner of Colorado and Collins of Maine are the only two GOP senators running for reelection in states that Trump lost; Collins opposes filling Ginsburg’s seat this year and Gardner is in line with McConnell. The rest of the party is fighting for reelection in states that Trump won, though some — like Arizona, North Carolina, Georgia and Texas — are becoming more fertile territory for Democrats.

“It obviously energizes the left, very much. The first two, Gorsuch and Kavanaugh, didn’t change the balance of the court. This one in all likelihood will,” said Sen. John Cornyn (R-Texas), who is up for reelection against Democrat MJ Hegar. “I’m not sure who it hurts and who it helps.”

And even though Democrats were unable to use the GOP’s 2016 blockade of Garland to their electoral advantage, they believe McConnell’s maneuver so close to the election is too craven to be lost on the electorate this time around.

“The American people do not want to see Mitch McConnell and Donald Trump go forward and steal a second Supreme Court seat,” said Sen. Elizabeth Warren (D-Mass.). McConnell “is going to a place that is contrary to what people want.”

In justifying their decision to move on a Supreme Court nomination this year, Republicans have pointed to the 2018 midterm elections, when the GOP slightly expanded its Senate majority after four Democratic senators who voted against Kavanaugh a month earlier were defeated. And the one Democrat who voted for Kavanaugh — Sen. Joe Manchin (D-W.V.) — was reelected in his ruby-red state.

“Recent history has clearly shown that these sorts of fighting bring Republicans together,” said Sen. Todd Young (R-Ind.), chairman of the Senate GOP’s campaign arm, who gave state-by-state presentations to the party on Tuesday. “And I anticipate that will happen in 2020, just as it did in 2016 and 2018.”

But Democratic Sen. Jon Tester won reelection in 2018 in conservative Montana after voting against Kavanaugh; Sen. Kyrsten Sinema (D-Ariz.) beat McSally after coming out against Kavanaugh, as did Democratic incumbents from Pennsylvania, Michigan, Ohio and Wisconsin — all states Trump won in 2016.

“They won a mandate in 2018? They lost the frickin’ House,” Tester said in an interview. “They’re making excuses for something that they know is totally corrupt.”

Marianne LeVine and James Arkin contributed to this report.