Iowa looms as a potential blockbuster on the Senate map — a contest Democrats need to put firmly in play as part of their takeover strategy. It’s not yet a top-tier race on the level of Arizona or North Carolina, but Democrats say they can win despite Iowa's lurch to the right in recent years, including Ernst's 2014 victory and Donald Trump's decisive win in 2016.

All of this is playing out as in-person campaigning has been all but eliminated, and as candidates are scrambling to execute get-out-the-vote plans in the first major Senate contest happening during the pandemic.

“We are in an election cycle like we've never seen before,” said Charlie Wishman, the president of the Iowa AFL-CIO, which endorsed Greenfield and is hitting phone banks to encourage members to vote for her by mail. “While it looks like Theresa Greenfield is in a really good spot to win this primary, I don't think anybody should take anything for granted whatsoever.”

The party has gone all in on Greenfield — who failed to make the ballot in 2018, her only previous run for office, because her congressional campaign manager forged signatures without her knowledge.

She entered the race as a virtual unknown, on equal footing with the other Democratic candidates: Nearly three in four Iowans, 73 percent, told a Des Moines Register poll in March they didn't have an opinion of her. But the same poll also showed significant slippage in Ernst's approval rating, a potential sign of vulnerability for a senator once viewed as a solid bet for reelection.

Republicans have taken notice: The National Republican Senatorial Committee, the Senate GOP’s official campaign arm, is prepared to strike, launching its first ads the week after the primary. It’s part of a planned air barrage with more than $15 million already on the books from GOP outside groups, their second-largest general election investment of any race so far.

Greenfield still needs to survive her first test: the primary. Limited public polling has shown her with an edge, and she has significantly outraised all of her opponents and boasts more on-the-ground support from unions and Iowa Democrats. Her campaign and outside groups supporting her combine for a more than 20-to-1 TV spending advantage over Democrats Michael Franken and self-funder Eddie Mauro, whose most recent ads have been attacks aimed at the frontrunner.

But despite an already overwhelming disparity, more help is on the way. EMILY’s List, which backed Greenfield immediately after she entered the race, is going negative against Franken, a former three-star Navy admiral who grew up in Iowa and moved back to run for the office. A super PAC affiliated with the group is set to spend nearly $1 million in ads attacking Franken’s recent return to Iowa and labeling the former Navy admiral a “Washington, D.C. defense contractor.”

Democrats aren't just trying to propel Greenfield to victory in the primary — they want her riding a wave of momentum headed into the general election. Mairead Lynn, a spokesperson for EMILY’s List, said in a statement Greenfield's opponents were “baselessly” attacking her, but her supporters remain confident she will defeat Ernst and “finally give Iowa voters what they deserve — a senator who fights for them."

Greenfield’s message has been focused on her upbringing on a farm and her first husband’s death on the job as an electrician, which occurred when she was a young mother, forcing her to rely on Social Security and union benefits.

She has also leaned on her local political operation, announcing endorsements from nearly three dozen additional Iowa Democrats Friday. Her latest TV ad highlighted backing from unions, members of the state’s congressional delegation and Amy Klobuchar (D-Minn.), Pete Buttigieg and Elizabeth Warren (D-Mass.), three of the top five finishers in this year's Iowa caucuses.

“That's how you win. You build a strong grassroots team right here in Iowa,” Greenfield said in a televised primary debate last week, touting her in-state fundraising. “I'm proud of that, and I'm going to continue to work hard, because that's what you need to do to win back this seat and defeat Sen. Ernst this fall.”

Greenfield's faced some friendly fire: Mauro, a businessman who has lost in previous runs for office, has trained his TV ads against her — something most Democrats believe is unlikely to boost his campaign but could damage Greenfield's image. Franken has touted his endorsement by the Des Moines Register, and his campaign pushed back aggressively on the attack from EMILY’s List.

Kimberley Boggus, Franken’s campaign manager, called the attack "shameful discrimination against those who have served their country" and Franken called for Greenfield to denounce it in a video posted by his campaign.

“It’s going to become clear to voters in the next few days the outside influence of money in this race," Boggus said in a statement. "Iowans need to decide what they want in Washington, more of the same or what they need? That is someone to take on Mitch McConnell and, at times, Chuck Schumer as well.”

All of the Senate Majority PAC advertising has been positive spots highlighting Greenfield’s biography, aimed at boosting her image. It's the second time this year the group has intervened in a primary. Ahead of the March primary in North Carolina, Senate Majority PAC sent nearly $13 million to two different outside groups to help boost DSCC-backed Cal Cunningham against an insurgent challenger, although some of that spending came after a Republican group meddled in the Democratic race.

Democrats are hoping to get a twofold benefit out of the spending: propel Greenfield in the primary and also increase her name ID among Iowa voters, most of whom don’t know her, before Republicans are on the airwaves attacking. The NRSC has reserved $2.6 million on TV starting one week after the primary and running through mid-July to attack the Democratic nominee. Senate Leadership Fund, a GOP super PAC, has more than $12 million booked for the fall.

“The more Democrats can do early on to define who our nominee is, the better that will serve them in the fall,” said Sam Roecker, who managed Democrat Patty Judge’s unsuccessful 2016 Senate campaign.

Republicans’ focus has been entirely trained on Greenfield, calling her beholden to Washington interests and hypocritical over her stated opposition corporate PAC donations. State GOP chair Jeff Kaufmann said after the primary debates last week he thought the contrast between Greenfield and Ernst, a first-term senator and military veteran, would be a major edge for Republicans.

"Theresa Greenfield's weaknesses as a candidate have been laid bare by members of her own party, and Chuck Schumer's special interest money can't fix this disaster," said Jesse Hunt, a spokesperson for the NRSC.

The relatively sleepy primary turned divisive last week during three separate debates. Mauro, Franken and Kimberly Graham, another candidate, attacked Greenfield for her fundraising and the outside intervention on her behalf. Greenfield said she doesn’t control the outside groups and had “nothing to say” about the intervention. But she also returned fire, arguing the other candidates hadn’t built grassroots support to match hers.

“If those people had the DSCC endorsement, they would gladly accept that help and everything that comes with it, too,” said Wishman, the AFL-CIO president.

Still, some Democrats beyond the candidates themselves remain irked by the intervention. Most don’t fault Greenfield or dismiss her chances in the fall, according to conversations with several Iowa Democrats, but are frustrated the outcome seemed predetermined.

One Iowa Democratic elected official, who is neutral in the race and spoke on condition of anonymity to discuss the intraparty matter, said Greenfield’s biggest differentiator is the resources behind her.

“If nothing else, it would have been great to see them compete on an even field,” the official said.