The 2020 Congressional-Retirement Tracker

Montana’s sole congressman is best known for assaulting a reporter on the eve of his victory in a House special election in 2017. Gianforte, a wealthy tech executive, won that race anyway, and a narrow election to a full term in 2018. But he’s running for governor in 2020, his second go at the office after losing to Democrat Steve Bullock in 2016. Regardless of how he does this time, his exit from Congress could make his House seat an easier hold for Republicans.

Roger Marshall, Kansas’s First Congressional District

• 2016 presidential election: +45 Trump
• 2018 House election: +36.2 Marshall

Marshall is running in a crowded primary for the seat that Senator Pat Roberts is vacating in retirement. The 59-year-old obstetrician is in just his second term in the House, beating conservative Representative Tim Huelskamp, a thorn in the side of party leadership, in a 2016 primary. The district, which covers more than half of Kansas, is the reddest in the state.

Paul Cook, California’s Eighth Congressional District

• 2016 presidential election: +15.1 Trump
• 2018 House election: +20 Cook

Cook, 76, is leaving the House after four terms and will try to serve closer to home: He plans to run for a seat on the Board of Supervisors in San Bernardino County. His Republican district stretches to the Nevada border and is one of the largest geographically in California.

House Democrats Running for Another Office in 2020

Ben Ray Luján, New Mexico’s Third Congressional District

• 2016 presidential election: +25.1 Clinton
• 2018 House election: +32.2 Luján

Luján is a top contender to take the retiring Udall’s Senate seat in New Mexico, 12 years after he took Udall’s House seat when the Democrat advanced across the Capitol. Though he now owns the title of assistant speaker in the Democratic leadership, Luján rose to stardom as the chairman of the party’s congressional arm in 2018, when Democrats picked up 40 seats and easily recaptured the House majority.

Joseph Kennedy III, Massachusetts’s Fourth Congressional District

• 2016 presidential election: +24.2 Clinton
• 2018 House election: Uncontested

The grandson of Robert F. Kennedy is vacating his House seat after four terms to challenge Senator Edward Markey in the Democratic primary. His decision sets up the highest-profile Democratic primary in the Senate, although Kennedy’s House seat should be an easy hold for his party.

Tulsi Gabbard, Hawaii’s Second Congressional District

• 2016 presidential election: +31.8 Clinton
• 2018 House election: +54.8 Gabbard

Gabbard announced in late October that she would not run for reelection to her House seat so that she could focus on her bid for the Democratic presidential nomination. Her decision to leave Congress after four terms was not, however, a sign that her long-shot White House campaign was taking off; instead, it was likely because an aggressive primary challenge from a Hawaii state senator had made it far from a sure thing that Gabbard could win back her seat even if she wanted to.

Died in Office

Representative Elijah Cummings, Maryland’s Seventh Congressional District

• 2016 presidential election: +55.6 Clinton
• 2018 House election: +55.2 Cummings

Cummings’s death in October at age 68 opened up his Baltimore congressional district for the first time in more than 20 years. His widow, Maya Rockeymoore Cummings, is reportedly eyeing a run for the seat in a special election, which Democrats are virtually assured of winning.

Saahil Desai contributed to this report.

Russell Berman is a staff writer at The Atlantic, where he covers politics.