The 2020 United States Senate election in Iowa was held on November 3, 2020, to elect a member of the United States Senate to represent the State of Iowa, concurrently with the 2020 U.S. presidential election, as well as other elections to the United States Senate in other states and elections to the United States House of Representatives and various state and local elections. Primaries were held on June 2. Incumbent Republican Senator Joni Ernst won re-election to a second term, defeating Democratic nominee Theresa Greenfield.
Most experts and pollsters considered this race and the concurrent presidential race as a tossup due to incumbent president Donald Trump's low approval ratings and Ernst's own popularity dropping in polls, partly due to a viral moment in a debate where she did not know the break-even price for soybeans. Despite this, Ernst was reelected by a larger-than-expected 6.6 points, while Trump simultaneously won the state with a bigger yet similarly unexpected margin of victory. Ernst carried an overwhelming majority of the state's counties including many rural ones, while Greenfield carried only eight counties: Polk, Linn, Scott, Johnson, Black Hawk, Story, Cerro Gordo and Jefferson.
On June 2, 2020, Theresa Greenfield won the Democratic primary with 47.71% of the vote, defeating three other major candidates, including Michael Franken, a retired U.S. Navy admiral and former aide to U.S. Senator Ted Kennedy.
Major media described the campaign as one of the most likely to decide control of the Senate after the 2020 election. Polls conducted after the primary showed a close contest between Greenfield and Ernst, with neither candidate leading by more than 4 points.
Through June 2020, Greenfield had raised $11.5 million, compared to $14.6 million for Ernst but by September, Greenfield had pulled ahead, raising $40.0 million compared to $21.6 million for Ernst. The race was expected to be the most expensive in the state's history, and the second most expensive Senate race in the United States, after the 2020 United States Senate election in North Carolina, where Cal Cunningham challenged Thom Tillis.
with Eddie Mauro<br />
with Joni Ernst and generic Democrat<br />
with Joni Ernst and Generic Opponent<br />
with generic Republican and generic Democrat<br />
Counties that flipped from Democratic to Republican
Counties that flipped from Republican to Democratic
Ernst carried all four congressional districts, including one that elected a Democrat.
Partisan clients<br />
Voter samples<br />
Official campaign websites