2020 United States Senate election in Iowa


The 2020 United States Senate election in Iowa will be 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.

Republican primary

Candidates

Nominee

Results

Democratic primary

Candidates

Nominee

Endorsements

Polling

Results

Other candidates

Libertarian Party

Nominee

Declared

Predictions

Endorsements

Polling

Aggregate Polling
Theresa Greenfield vs. Joni Ernst
Poll sourceDate
administered
Sample
size
Margin
of error
Joni
Ernst
Theresa
Greenfield
Other/Undecided
July 11–16, 2020701 ± 3.7%43%45%12%
June 23–28, 2020800 ± 3.5%47%49%4%
June 7–10, 2020674 ± 3.8%43%46%11%
June 6–8, 2020865 ± 3.8%45%48%6%
June 3–4, 2020963 ± 3.4%43%45%12%
April 30 – May 1, 20201,222 ± 2.8%43%42%14%
December 13–15, 2019944 ± 3.4%47%41%12%
October 13–16, 2019888 ± 3.2%47%40%14%
April 24–29, 2019500 ± 4.4%56%34%

;with Eddie Mauro
Poll sourceDate
administered
Sample
size
Margin
of error
Joni
Ernst
Eddie
Mauro
Undecided
May 7–9, 2020632± 3.9%42%42%
April 24–29, 2019500 ± 4.4%58%33%
April 24–29, 2019500 ± 4.4%49%44%

;with Joni Ernst and generic Democrat
Poll sourceDate
administered
Sample
size
Margin
of error
Joni
Ernst
Generic
Democrat
Undecided
April 29–30, 2019780± 3.5%48%44%
June 30July 1, 2017784± 3.6%48%41%12%

;with Joni Ernst and Generic Opponent
Poll sourceDate
administered
Sample
size
Margin
of error
Joni
Ernst
Generic
Opponent
OtherUndecided
March 2–5, 2020667 ± 3.8%41%31%3%26%

;with generic Republican and generic Democrat
Poll sourceDate
administered
Sample
size
Margin
of error
Generic
Republican
Generic
Democrat
Undecided
April 24–29, 2019500 ± 4.4%45%41%

Results