United States Senate elections, 2018

Partisan composition

Among the 34 Senators up for election in 2018 are 33 Class I Senators up for regular election and 1 Class II Senator up for special election. These consist of 23 Democrats, 2 independents who caucus with the Senate Democrats, and 9 Republicans. If a Senate vacancy occurs between 2016 and 2018, there may be special elections before or during the 2018 election, depending on state law.

Most recent election predictions

Democrats are expected to target the Senate seats in Nevada and Arizona. Democrats could also target Texas. Republicans are expected to target Democratic-held seats in Indiana, Missouri, Montana, North Dakota, and West Virginia, all of which voted for Mitt Romney in the 2012 election and Donald Trump in the 2016 election, as well as seats in Florida, Ohio, Pennsylvania, Wisconsin, and Michigan, all of which voted for Donald Trump in the 2016 election. Republicans could also target seats in Minnesota, Virginia, Maine, and New Jersey. Other races may also become competitive.

Elections during the 115th Congress

In this election, the winner will be seated during 2018 or in 2019 before January 3.

Elections leading to the 116th Congress

In these general elections, the winners will be elected for the term beginning January 2019.

All of the elections involved the Class 1 seats; ordered by state.

Complete list of races

Thirty-three seats are up for election in 2018:

Alabama (special)

With the appointment of Jeff Sessions as U.S. Attorney General, Alabama Attorney General Luther Strange was appointed by Governor Robert J. Bentley to the seat on February 9, 2017. He had declared his candidacy for the seat before the election. He will be 65 years old in 2018.

Arizona

One-term Republican Senator Jeff Flake was elected with 49% of the vote in 2012. He will be 55 years old in 2018. He is running.

Former state senator Kelli Ward is running as a Republican.

California

Four-term Democratic Senator Dianne Feinstein won a special election in 1992 and was elected to full terms in 1994, 2000, 2006, and 2012. She won re-election in 2012 with 63% of the vote, taking the record for the most popular votes in any U.S. Senate election in history, having received 7.75 million votes. Feinstein is the Ranking Member of the Select Committee on Intelligence. She will be 85 years old in 2018. She is running for re-election.

Independent candidate biologist Michael Eisen is running.

Connecticut

One-term Democratic Senator Chris Murphy was elected with 55% of the vote in 2012. He will be 45 years old in 2018. He is running for reelection.

Delaware

Three-term Democratic Senator Tom Carper won re-election with 66% of the vote in 2012. He will be 71 years old in 2018.

Businessman Chuck Boyce is running for the Republican nomination.

Florida

Three-term Democratic Senator Bill Nelson was re-elected with 55% of the vote in 2012. Nelson is the Ranking Member of the United States Senate Committee on Commerce, Science and Transportation. Nelson will be 76 years old in 2018. He has strongly hinted he will seek re-election to a fourth term in office.

Hawaii

One-term Democratic Senator Mazie Hirono was elected with 63% of the vote in 2012. She will be 71 years old in 2018.

Indiana

One-term Democratic Senator Joe Donnelly was elected with 50.04% of the vote in 2012. He will be 63 years old in 2018. He is running.

Attorney Mark Hurt is running for the Republican nomination.

Maine

One-term Independent Senator Angus King was elected in a three-way race with 53% of the vote in 2012. King has caucused with the Democratic Party since taking office in 2013, but he has left open the possibility of caucusing with the Republican Party in the future. This Senate election is scheduled to be the first in Maine to be conducted with ranked choice voting, as opposed to a simple plurality, after voters passed a citizen referendum approving the change in 2016. King has indicated he will seek reelection. He will be 75 years old in 2018.

Former Democratic State Representative Diane Russell is considering running.

Republican Governor of Maine Paul LePage has stated he will run unless hired by Donald Trump's administration.

Maryland

Two-term Democratic Senator Ben Cardin was re-elected with 56% of the vote in 2012. He will be 75 years old in 2018.

Massachusetts

One-term Democratic Senator Elizabeth Warren was elected with 54% of the vote in 2012. She will be 69 years old in 2018. In January 2017, Warren announced through her Facebook page that she will seek reelection in 2018.

Michigan

Three-term Democratic Senator Debbie Stabenow was re-elected with 59% of the vote in 2012. Stabenow is Ranking Member of the Senate Agriculture Committee. She will be 68 years old in 2018. She is running.

Minnesota

Two-term Democratic Senator Amy Klobuchar was re-elected with 65% of the vote in 2012. She will be 58 years old in 2018. She is running.

Mississippi

One-term Republican Senator Roger Wicker won re-election with 57% of the vote in 2012. He was appointed in 2007 and won a special election in 2008 to serve the remainder of Trent Lott's term. He will be 67 years old in 2018.

Missouri

Two-term Democratic Senator Claire McCaskill was re-elected with 55% of the vote in 2012. She will be 65 years old in 2018. She is running.

Montana

Two-term Democratic Senator Jon Tester was re-elected with 49% of the vote in 2012. He will be 62 years old in 2018. He is running.

Ryan Zinke resigned from the House of Representatives to become United States Secretary of the Interior. He could step down from that position to run for the Senate seat.

Nebraska

One-term Republican Senator Deb Fischer was elected with 56% of the vote in 2012. She will be 67 years old in 2018.

Nevada

One-term Republican Senator Dean Heller was elected with 46% of the vote in 2012. He had been appointed to the seat in 2011. He will be 58 years old in 2018. Heller considered running for governor, but has since chosen to seek reelection.

New Jersey

Two-term Democratic Senator Bob Menendez was re-elected with 59% of the vote in 2012. Menendez was originally appointed to the seat in January 2006. He will be 64 years old in 2018. He is running.

New Mexico

One-term Democratic Senator Martin Heinrich was elected with 51% of the vote in 2012. He will be 47 years old in 2018. He is running.

New York

One-term Democratic Senator Kirsten Gillibrand was elected with 72% of the vote in 2012. She had previously been appointed to the seat in 2009, and won a special election to remain in office in 2010. She will be 51 years old in 2018. She is running.

Former United States Ambassador to Japan Caroline Kennedy, daughter of former President John F. Kennedy is reportedly considering running as a Democrat, 9 years after declining to replace Hillary Clinton's vacant seat after becoming U.S. Secretary of State.

North Dakota

One-term Democratic Senator Heidi Heitkamp was elected with 50% of the vote in 2012. She will be 63 years old in 2018.

Ohio

Two-term Democratic Senator Sherrod Brown was re-elected with 51% of the vote in 2012. He will be 65 years old in 2018. He is running.

Ohio State Treasurer Josh Mandel is running for the Republican nomination.

Many Conservative groups are urging Ohio Governor John Kasich to run.

Pennsylvania

Two-term Democratic Senator Bob Casey, Jr. was re-elected with 54% of the vote in 2012. He will be 58 years old in 2018. He is running.

Republican candidates include Pennsylvania House of Representatives member Rick Saccone

In addition, Libertarian candidate Dale Kerns has announced his candidacy for this seat.

Rhode Island

Two-term Democratic Senator Sheldon Whitehouse was reelected with 64% of the vote in 2012. He will be 63 years old in 2018. He is running.

Tennessee

Two-term Republican Senator Bob Corker was re-elected with 65% of the vote in 2012. Corker is the Chairman of the United States Senate Committee on Foreign Relations. He will be 66 years old in 2018. Corker may run for Governor of Tennessee in 2018. Senator Corker has also filed his Statement of Candidacy with the Secretary of the U.S. Senate to run for reelection to the U.S. Senate seat he currently holds in 2018.

Larry Crim, a perennial candidate, is running for the Republican nomination.

Texas

One-term Republican Senator Ted Cruz was elected with 57% of the vote in 2012. Cruz is running for re-election. He will be 48 years old in 2018.

U.S. Representative Beto O'Rourke is seeking the Democratic nomination for Senate, and U.S. Representative Joaquin Castro is considering a bid for the Democratic nomination for Senate.

Utah

Seven-term Republican Senator Orrin Hatch was re-elected with 65% of the vote in 2012. Hatch is the President pro tempore of the United States Senate, as well as the second most-senior Senator. Hatch is the chairman of the Senate Finance Committee. He will be 84 years old in 2018. Before the 2012 election, Hatch said that he would retire at the end of his seventh term if he was re-elected. However he has since "left the door ajar", but denied that he had changed his mind until March 9, 2017, when he announced his re-election campaign.

Former Governor of Massachusetts and 2012 presidential nominee Mitt Romney is reportedly considering running as a Republican, should Senator Hatch retire by 2018. Romney will be 71 years old in 2018.

Vermont

Two-term Independent Senator Bernie Sanders was re-elected with 71% of the vote in 2012. Sanders, one of two independent members of Congress, is a self-described democratic socialist. Sanders has caucused with the Democratic Party since taking office in 2007, and he is the Ranking Member of the Budget Committee. In November 2015, Sanders announced his plans to run as a Democrat rather than an Independent in all future elections. He will be 77 years old in 2018. On July 28, 2016, Sanders announced he would return to the Senate as an Independent and two days later in an interview on Real Time with Bill Maher that he would run for re-election.

Activist and journalist Al Giordano has stated he intends to challenge Sanders for the Democratic nomination to protest Sanders' 2016 presidential campaign, which Giordano claims has divided the Democratic Party.

Virginia

One-term Democratic Senator Tim Kaine was elected with 53% of the vote in 2012. He will be 61 years old in 2018. He is running for re-election.

Washington

Three-term Democratic Senator Maria Cantwell was re-elected with 61% of the vote in 2012. Cantwell is the Ranking Member of the Committee on Energy and Natural Resources. She will be 60 years old in 2018.

West Virginia

One-term Democratic Senator Joe Manchin was elected with 61% of the vote in 2012. He originally won the seat in a 2010 special election. Manchin is running for re-election.

Wisconsin

One-term Democratic Senator Tammy Baldwin was elected with 51% of the vote in 2012. She is the first openly gay Senator in U.S. history. She will be 56 years old in 2018. She is running.

Wyoming

One-term Republican Senator John Barrasso was elected with 76% of the vote in 2012. Barrasso was appointed to the seat in 2007, and won a special election in 2008. Barrasso is the Chairman of the Senate Committee on Indian Affairs. He will be 66 years old in 2018.