The 2018 United States Senate election in Indiana took place on November 6, 2018, along with other elections to the United States Senate and House of Representatives and various state and local elections. Incumbent Democratic U.S. Senator Joe Donnelly sought re-election to a second term, facing Republican businessman and former state representative Mike Braun and Libertarian Party nominee Lucy Brenton. Braun defeated Donnelly in the general election by a margin of 6 percent. He has declined to seek re-election in 2024 and is instead running for Governor that year.
In 2017, Politico described the race as "possibly the GOP's best opportunity to seize a Senate seat from Democrats" in the 2018 elections. The primary election was held on May 8, 2018. In October 2018, RealClearPolitics rated the race a toss-up between the Democratic and Republican nominees, with the Libertarian receiving a poll average of 6%.
Background
In 2012, Joe Donnelly was elected to the Senate with 50% of the vote to Republican nominee Richard Mourdock's 44%. In the 2016 presidential election, Republican nominee Donald Trump won Indiana with about 56.5% of the vote to Democratic nominee Hillary Clinton's 37.5%.
Democratic primary
Candidates
Nominee
Joe Donnelly, incumbent U.S. Senator
Withdrew
Martin Del Rio, Iraq War veteran
Endorsements
Results
Republican primary
Candidates
Nominee
Mike Braun, businessman and former state representative
Eliminated in the primary election
Luke Messer, U.S. Representative
Todd Rokita, U.S. Representative
Declined
Jim Banks, U.S. Representative
Susan Brooks, U.S. Representative (endorsed Luke Messer) Mike Delph, state senator (endorsed Todd Rokita) Jackie Walorski, U.S. Representative
Withdrawn
Terry Henderson, businessman (endorsed Mike Braun) Andy Horning, Libertarian nominee for the U.S. Senate in 2012 and Libertarian nominee for IN-08 in 2014 Mark Hurt, attorney and former congressional aide Andrew Takami, director of Purdue Polytechnic New Albany (endorsed Luke Messer)
Endorsements
Polling
Results
Independent
Candidates
Declared
James Johnson, Jr.
General election
Candidates
Mike Braun, businessman and former state representative (R) Lucy Brenton (L) Joe Donnelly, incumbent (D) James Johnson, Jr. (I)
Debates
Complete video of debate, October 8, 2018
Predictions
Fundraising
Endorsements
Polling
Graphical summary
with Todd Rokita
with Luke Messer
with generic Republican
Results
On November 6, 2018, Braun won the general election. He swept southern Indiana, the exurbs of Indianapolis, and most other rural areas in the state. Donnelly ran well behind his 2012 vote totals, winning only in Indianapolis, the university centers (Bloomington, Terre Haute, West Lafayette, South Bend), and the suburbs of Chicago in Northwest Indiana.
Counties that flipped from Democratic to Republican
Madison (largest city: Anderson) Spencer (largest city: Santa Claus) Starke (largest city: Knox) Vanderburgh (largest city: Evansville) Scott (Largest city: Scottsburg) Blackford (Largest city: Hartford City) Clark (Largest city: Jeffersonville) Crawford (Largest city: Marengo) Floyd (Largest city: New Albany) Jefferson (Largest city: Madison) Fayette (Largest city: Connersville) Henry (Largest city: New Castle) Howard (Largest city: Kokomo) Wayne (Largest city: Richmond) Vermillion (largest city: Clinton) Perry (largest city: Tell City) Sullivan (Largest city: Sullivan)
By congressional district
Braun won 6 of 9 congressional districts, with Donnelly winning the other 3, including one held by a Republican.