Finkenauer, 32, became the second-youngest woman ever elected to Congress when she won during the Democratic wave of 2018. But she was defeated two years later in one of the most closely watched congressional races in the country as Republicans rolled back many of Democrats’ earlier gains.
An early endorser of President Joe Biden and the daughter of a welder and public school teacher, Finkenauer emphasized the working class and those being "left behind" in her Senate announcement video.
Finkenauer told the Des Moines Register that the Jan. 6 attack on the Capitol helped convince her to run and in her video laid blame at the feet of Republicans like Grassley for not protecting democracy.
“The politicians who have been there for decades don’t really want people like us there. They think they own democracy, and they were silent when it was attacked,” she said in the video. “It’s politicians like Sen. Grassley and Mitch McConnell who should know better but are so obsessed with power they oppose anything that moves us forward.”
Grassley, 87, hasn't said whether he’ll seek an eighth term in the Senate, but he would be the heavy favorite in a state former President Donald Trump won twice and which Grassley has represented in Washington for over 45 years.
He raised $625,000 in the last quarter, a relatively modest sum for a Senate incumbent heading into an election year, but has more than $2.5 million banked away.
In a statement, a spokeswoman for the National Republican Senatorial Committee, Katharine Cooksey, framed Finkenauer as too liberal for the state.
"Abby Finkenauer and her far-left positions are indistinguishable from those of Bernie Sanders, AOC, and the socialist squad, so it’s not surprising Iowans fired her just last year," she said.
So far, Finkenauer is the highest-profile Democrat in the race. Rep. Cindy Axne, the only Democrat left in Iowa’s four-member congressional delegation, hasn't ruled out a bid, and former county supervisor Dave Muhlbauer is the other Democrat running right now.
Finkenauer hails from Dubuque County, part of a stretch of working-class Iowa counties along the Mississippi River that were once reliably Democratic but saw some of the biggest swings to the right in the country under Trump.
Former President Barack Obama won Iowa twice and carried Dubuque County by more than 20 percentage points in 2008, but Trump beat both Hillary Clinton and Biden, who was the first Democrat to win the presidency since Franklin Delano Roosevelt without carrying Dubuque County.
"The fate of Finkenauer as a candidate rests on whether or not Grassley runs," said Jessica Taylor, an analyst with the nonpartisan Cook Political Report. "This is a Republican seat at its heart. And someone with such long ties to the state that’s been re-elected easily like Grassley would be the clear favorite."
Iowa’s other senator, Republican Joni Ernst, won re-election last year 52 percent to 45 percent, despite being vastly outspent by her Democratic opponent, Theresa Greenfield, who also had more support from super PACs and outside groups.
Still, Finkenauer proved to be a prodigious fundraiser during her two congressional races and built a national profile, which could help make the race competitive and force national Republicans to divert resources to Iowa.
"Democrats have much better targets on the board to keep and expand on their majority than Iowa," Taylor added.
The Senate is currently split 50-50, with Vice President Kamala Harris casting the decisive vote for Democrats, meaning a swing of even a single seat could have enormous consequences in the 2022 midterms.