Dozens of states will hold Senate primaries this year, beginning with Texas on Tuesday. Here is a look at the key races in every state. The outlook of each contest is based on an analysis of data from the Cook Political Report and from Larry Sabato, a professor of politics at the University of Virginia.
Republicans need morethan 50 seats for majority
| Primary | State | State of the RaceCurrently |
|---|
| Primary | State | State of the RaceCurrently |
|---|---|---|
| March 4 |
Texas
Primary on March 4
John Cornyn, the Senate’s No. 2 Republican, easily beat his main primary challenger, Representative Steve Stockman, and avoided a runoff.
|
John Cornyn
has held the seat since 2002.
Doug Mills for The New York Times
|
| March 18 |
Illinois
Primary on March 18
Richard J. Durbin is the second-most powerful Democrat in the Senate. This seat is likely to remain blue for at least six more years.
|
Richard Durbin
has held the seat since 1997.
Stephan Savoia/Associated Press
|
| May 6 |
North Carolina
Primary on May 6
Senator Kay Hagan is the No. 1 target of Americans for Prosperity, the powerful conservative group backed by the Koch brothers. In November, she will square off against one of three contenders for the G.O.P. nomination: a powerful state legislator, a Tea Party candidate or a social conservative.
|
Kay Hagan
has held the seat since 2009.
Philip Scott Andrews for The New York Times
|
| May 13 |
Nebraska
Primary on May 13
Conservative groups are split between the two Republican front-runners to replace retiring Senator Mike Johanns: former State Treasurer Shane Osborn and Ben Sasse, the president of Midland University, who served as an assistant secretary of health and human services under President George W. Bush.
|
Retiring Senator Mike Johanns has held the seat since 2009.
No Incumbent
|
| May 13 |
West Virginia
Primary on May 13
Republicans are optimistic that their likely nominee, Representative Shelley Moore Capito, can break the Democrats' longtime lock on the state's Senate seats. Natalie Tennant, West Virginia's secretary of state and the likely Democratic nominee, will distance herself from President Obama.
|
Retiring Senator John D. Rockefeller IV has held the seat since 1985.
No Incumbent
|
| May 20 |
Arkansas
Primary on May 20
Senator Mark Pryor is trying to hold on to his seat in what will be a difficult race against Tom Cotton, a freshman representative who is supported by both Tea Party and establishment factions.
|
Mark Pryor
has held the seat since 2003.
Danny Johnston/Associated Press
|
| May 20 |
Georgia
Primary on May 20
Michelle Nunn, the daughter of former Senator Sam Nunn, could be the Democrats' best chance to pick up a seat. Ms. Nunn, who led the Points of Light Foundation, the volunteer group inspired by the elder George Bush, is positioning herself as a centrist. Some Republicans fear that a crowded G.O.P. contest will produce a nominee too far to the right to win in November.
|
Retiring Senator Saxby Chambliss has held the seat since 2003.
No Incumbent
|
| May 20 |
Idaho
Primary on May 20
Senator Jim Risch should easily win re-election against his Democratic opponent, a lawyer who spent most of his career outside Idaho.
|
Jim Risch
has held the seat since 2009.
J. Scott Applewhite/Associated Press
|
| May 20 |
Kentucky
Primary on May 20
The Kentucky G.O.P. primary has gotten a lot of national attention, but Senator Mitch McConnell is expected to survive a challenge from Matt Bevin, a Louisville businessman with endorsements from several conservative groups. At the same time, Bluegrass Democrats are united around a candidate for the first time in decades. Polls indicate that Alison Lundergan Grimes, Kentucky's secretary of state, could give the most powerful Republican in the Senate a strong challenge in November.
|
Mitch McConnell
has held the seat since 1985.
Win McNamee/Getty Images
|
| May 20 |
Oregon
Primary on May 20
Senator Jeff Merkley could be in for a tougher-than-expected race in deep-blue Oregon if a Portland pediatric neurosurgeon, Monica Wehby, wins the Republican nomination. She is a moderate who could resonate with Oregonians suffering from Obama fatigue.
|
Jeff Merkley
has held the seat since 2009.
Mark Wilson/Getty Images
|
| June 3 |
Alabama
Primary on June 3
Jeff Sessions is likely to be re-elected.
|
Jeff Sessions
has held the seat since 1997.
Chris Kleponis/Getty Images
|
| June 3 |
Iowa
Primary on June 3
The race for the G.O.P. nomination to replace retiring Senator Tom Harkin is a test case for the battle between Tea Party and establishment Republicans. Representative Bruce Braley, running unopposed for the Democratic nomination, is hoping that a bruising Republican primary will help keep the seat on the Democratic side of the aisle.
|
Retiring Senator Tom Harkin has held the seat since 1985.
No Incumbent
|
| June 3 |
Mississippi
Primary on June 3
The Mississippi G.O.P. establishment is rallying around Thad Cochran, the second-most senior Republican in the Senate, to fend off a challenge from the Tea Party insurgent Chris McDaniel, a state senator who is backed by several conservative advocacy groups.
|
Thad Cochran
has held the seat since 1978.
Brendan Smialowski/Getty Images
|
| June 3 |
Montana
Primary on June 3
The state offers a pickup opportunity for Republicans, but the appointment of Lt. Gov. John Walsh to serve the remaining term of Max Baucus, who resigned to be United States ambassador to China, gives Democrats a chance against the Republican candidate, Representative Steve Daines.
|
John Walsh
has held the seat since 2014.
Eliza Wiley/Associated Press
|
| June 3 |
New Jersey
Primary on June 3
Cory Booker, the former mayor of Newark who won a special election last fall to replace the late Senator Frank Lautenberg, will not have a big-name Republican opponent in November.
|
Cory Booker
has held the seat since 2013.
William B. Plowman/NBC
|
| June 3 |
New Mexico
Primary on June 3
Tom Udall is making his first bid for re-election after winning the seat held for more than 30 years by Pete V. Domenici, a Republican who retired in 2009.
|
Tom Udall
has held the seat since 2009.
Ron Edmonds/Associated Press
|
| June 3 |
South Dakota
Primary on June 3
The seat of retiring Senator Tim Johnson should be a strong pickup opportunity for Republicans, but Larry Pressler's decision to run as an independent inserts a dose of uncertainty into the race. Mr. Pressler is a moderate Republican who served three terms in the Senate before losing his seat to Mr. Johnson in 1996. Former Gov. Mike Rounds is the likely Republican nominee, and Rick Weiland, a former aide to Tom Daschle, is the lone Democrat in the race.
|
Retiring Senator Tim Johnson has held the seat since 1997.
No Incumbent
|
| June 10 |
Maine
Primary on June 10
In November, Susan Collins, one of the last moderate Republicans in the Senate, will go up against Shenna Bellows, a Democrat who has been called "the Elizabeth Warren of civil liberties." It is unclear if Ms. Bellows poses a serious threat.
|
Susan Collins
has held the seat since 1997.
Chip Somodevilla/Getty Images
|
| June 10 |
South Carolina
Primary on June 10
Tim Scott was appointed to the Senate in 2012 to replace the Tea Party icon Jim DeMint, who resigned to head the Heritage Foundation. Mr. Scott is not facing any Republican challengers.
|
Tim Scott
has held the seat since 2012.
Doug Mills for The New York Times
|
| June 10 |
South Carolina
Primary on June 10
Lindsey Graham faces a handful of primary challengers running to his right. The two-term Republican incumbent needs more than 50 percent of the vote to avoid a runoff.
|
Lindsey Graham
has held the seat since 2003.
Chip Somodevilla/Getty Images
|
| June 10 |
Virginia
Primary on June 10
The entry of Ed Gillespie, former chairman of the Republican National Committee, into the G.O.P. race has added a level of intensity to what otherwise would have been a cakewalk for the Democratic incumbent, Mark Warner.
|
Mark Warner
has held the seat since 2009.
Mary Calvert/Associated Press
|
| June 24 |
Colorado
Primary on June 24
Colorado’s Senate race became more competitive at the end of February, when Representative Cory Gardner, a top-tier Republican, announced he would challenge the incumbent, Mark Udall. Until that point, Mr. Udall had attracted only opponents whose campaigns were struggling to gain traction.
|
Mark Udall
has held the seat since 2009.
Charles Dharapak/Associated Press
|
| June 24 |
Oklahoma
Primary on June 24
James M. Inhofe is expected to be re-elected.
|
James Inhofe
has held the seat since 1994.
Alex Wong/Getty Images
|
| June 24 |
Oklahoma
Primary on June 24
Senator Tom Coburn's decision to retire at the end of the current session opened up his seat two years earlier than expected. Representative James Lankford is the Republican front-runner.
|
Retiring Senator Tom Coburn has held the seat since 2005.
No Incumbent
|
| Aug. 5 |
Kansas
Primary on Aug. 5
Senator Pat Roberts faces a long-shot Tea Party primary challenger, Milton Wolf — a radiologist who is a distant cousin of President Obama's.
|
Pat Roberts
has held the seat since 1997.
J. Scott Applewhite/Associated Press
|
| Aug. 5 |
Michigan
Primary on Aug. 5
The race to replace Senator Carl Levin, a Democrat who is retiring, is shaping up to be a pickup opportunity for the Republicans. Terri Lynn Land, Michigan's former secretary of state and the likely Republican nominee, has a slight lead over Representative Gary Peters, the Democrat.
|
Retiring Senator Carl Levin has held the seat since 1979.
No Incumbent
|
| Aug. 7 |
Tennessee
Primary on Aug. 7
State Representative Joe Carr is challenging the two-term incumbent, Lamar Alexander, but Mr. Carr's chances to win the Republican nomination are slim.
|
Lamar Alexander
has held the seat since 2003.
T.J. Kirkpatrick/Getty Images
|
| Aug. 9 |
Hawaii
Primary on Aug. 9
Shortly before he died, Senator Daniel K. Inouye, a Democrat, asked Gov. Neil Abercrombie to appoint Representative Colleen Hanabusa to his seat. Mr. Abercrombie chose his lieutenant governor, Brian Schatz, instead. Now, Mr. Schatz and Ms. Hanabusa are competing to fill the remaining two years of Mr. Inouye's term.
|
Brian Schatz
has held the seat since 2012.
T.J. Kirkpatrick for The New York Times
|
| Aug. 12 |
Minnesota
Primary on Aug. 12
Senator Al Franken may have a credible challenger with the entry of the multimillionaire businessman Mike McFadden, a Republican, into the race.
|
Al Franken
has held the seat since 2009.
Jonathan Ernst/Reuters
|
| Aug. 19 |
Alaska
Primary on Aug. 19
In 2008, Mark Begich was the first Democrat elected to the Senate from Alaska since 1974. He may not make it another term. Republicans Dan Sullivan and Mead Treadwell are competing for establishment support against Joe Miller, the Tea Party candidate who famously beat Senator Lisa Murkowski in the 2010 primary only to lose to her write-in campaign during the general election.
|
Mark Begich
has held the seat since 2009.
Michael Reynolds/EPA
|
| Aug. 19 |
Wyoming
Primary on Aug. 19
Liz Cheney's decision to drop out of the Republican primary contest means Senator Michael B. Enzi is expected to be elected to a fourth term.
|
Mike Enzi
has held the seat since 1997.
Justin Edmonds for The New York Times
|
| Sept. 9 |
Delaware
Primary on Sept. 9
Senator Chris Coons, who won a special election in 2010 for the seat previously held by Vice President Joseph R. Biden Jr., is expected to win again.
|
Chris Coons
has held the seat since 2010.
Chip Somodevilla/Getty Images
|
| Sept. 9 |
New Hampshire
Primary on Sept. 9
Senator Jeanne Shaheen’s hold on New Hampshire will become uncertain if Scott Brown, a former senator in Massachusetts, enters the Republican primary. Otherwise, Ms. Shaheen is expected to keep the seat.
|
Jeanne Shaheen
has held the seat since 2009.
Chip Somodevilla/Getty Images
|
| Sept. 9 |
Rhode Island
Primary on Sept. 9
Senator Jack Reed, a Democrat, appears certain to be re-elected to a fourth term.
|
Jack Reed
has held the seat since 1997.
J. Scott Applewhite/Associated Press
|
| Sept. 9 |
Massachusetts
Primary on Sept. 9
Edward J. Markey won a special election in June to fill the remainder of John Kerry’s term after Mr. Kerry was confirmed as secretary of state. Mr. Markey is seeking his first full six-year term.
|
Ed Markey
has held the seat since 2013.
Josh Reynolds/Associated Press
|
| Nov. 4 ** |
Louisiana
Primary on Nov. 4 **
A Democrat in an increasingly red state, Senator Mary L. Landrieu narrowly won the 1996 and 2002 elections, and was re-elected in 2008 with help from a large African-American turnout. The Republican establishment candidate, Representative Bill Cassidy, must beat the Tea Party favorite, Rob Maness, before facing Ms. Landrieu.
|
Mary Landrieu
has held the seat since 1997.
Philip Scott Andrews for The New York Times
|