Tuesday’s congressional primaries will mark the beginning of the end for some House members, and others are at risk of losing to primary challengers. House members in California and Texas are giving up safe seats for the chance to serve in the Senate. A member-on-member battle in Alabama will see one second-term member lose his seat. And a nearly 30-year incumbent from Houston is facing a strong challenge from her former intern.

Those are some of the key races that will be decided on Super Tuesday. While 15 states and one territory will hold presidential primaries on March 5, voters in a handful of states will also choose nominees for this year’s House and Senate races. Here’s what you need to know:

California

Senate: An expensive Senate primary is unfolding in California, where three Democratic House members — Barbara Lee, Adam B. Schiff and Katie Porter — are vying for the seat that had been held by Sen. Dianne Feinstein for more than three decades. Lee and Schiff are giving up their safe seats, while Porter’s Orange County district is a battleground that she narrowly won in 2022. 

• More previews of March 5 primaries
• [Some members of Congress not sweating reelection this year]
• [Alabama, Arkansas races to watch on Super Tuesday]
• [California has no shortage of key House races on Tuesday]
• [Three questions North Carolina primaries may answer]
• [Key races to watch in Texas on Super Tuesday]

The three Democrats are among more than two dozen candidates on the primary ballot. The leading GOP contender is former Major League Baseball star Steve Garvey, who spent less than $1.4 million but was featured in many of Schiff’s ads as a Republican boogeyman, messaging that may have been designed to boost Garvey’s support from conservatives and keep Porter off the November ballot. Under California’s election rules, the top two finishers, regardless of party affiliation, will face off in November.

22nd District: Both parties are holding competitive primaries in this central California battleground district. Republican Rep. David Valadao, a dairy farmer seeking his sixth term, faces a challenge from the right from Chris Mathys, a former member of the Fresno City Council. Valadao is one of two Republicans left in Congress who voted to impeach Trump after his supporters attacked the Capitol on Jan. 6, 2021. On the Democratic side, former state Assemblymember Rudy Salas, the preferred candidate of the Democratic Congressional Campaign Committee and most of the state’s Democratic establishment, is competing with state Sen. Melissa Hurtado. Salas came within 3,100 votes of defeating Valadao in 2022, and super PACs tied to both parties’ House leadership have spent $1.6 million combined on the race. 

Texas

Senate: Rep. Colin Allred is giving up a safe blue House seat to try to unseat Republican Sen. Ted Cruz. But first Allred has to get by a fellow Democrat, state Sen. Roland Gutierrez. At the beginning of the year, Allred had a $3.9 million fundraising edge over Cruz, but he’s had to dip into that war chest in his effort to fend off Gutierrez. Eight other Democrats are also running, but Allred and Gutierrez, who gained attention questioning authorities’ response to the mass shooting at an elementary school in Uvalde, are widely seen as the top contenders. A poll by the Texas Politics Project at the University of Texas at Austin released last week put Allred ahead with 52 percent of the vote to Gutierrez’s 14 percent. If those numbers hold, Allred would avoid a runoff, but if he doesn’t clear 50 percent, the top two finishers will meet again in May.

18th District: After Rep. Sheila Jackson Lee announced she was running for mayor of Houston, her former intern, attorney Amanda Edwards, jumped into the race for the soon-to-open congressional seat. But in December, Jackson Lee lost the mayoral runoff and decided she would seek a 16th term in Congress after all. Edwards, who is pitching herself as the voice of a new generation, had $669,000 on hand as of Feb. 14 to Jackson Lee’s $225,000. Jackson Lee had support from the campaign account of House Democratic leader Hakeem Jeffries of New York.

23rd District: Republican Rep. Tony Gonzales endured criticism from members of his own party for backing legislation codifying same-sex marriage and for his stance on border security. He also supported a bipartisan gun safety bill passed after the May 2022 mass shooting in Uvalde, which is in the district. The moderate from San Antonio was censured by the Texas GOP and now faces challenges on the right. His Republican opponents include Victor Avila, a retired special supervisory agent with Immigration and Customs Enforcement; Julie Clark, the former chairwoman of the Medina County Republican Party; Brandon Herrera, a YouTube personality and Second Amendment activist; and Frank Lopez Jr., a retired Border Patrol agent. Gonzales had $1.4 million on hand in mid-February, and three outside groups had spent $776,000 supporting him. The opponent with the most money going into the primary was Herrera, with $297,000.

Alabama

1st District: The member-on-member race between Reps. Jerry Carl and Barry Moore will end the House career of one of the two Republicans, both in their second terms. Both candidates have tried to paint themselves as more in line with today’s Republican Party, focusing on issues like their efforts to control the border in campaign ads. Carl has the edge in fundraising, and outside groups have been supporting both candidates. Additionally, 21 of their House colleagues contributed to one or both of the campaigns as of Feb. 14. The primary resulted from court-ordered redistricting that redrew the 2nd District, which Moore won with 69 percent of the vote in 2022, into one Democrats are well positioned to capture in November. 

Arkansas

3rd District: Rep. Steve Womack, a senior appropriator and former chairman of the Budget Committee, faces a primary challenge from state Sen. Clint Penzo. He’s the only member of the four-person Arkansas delegation to have a primary challenger on Tuesday. 

Since Womack’s 2010 election he’s easily defeated primary challengers when he’s faced them, most recently in 2022, when he won the GOP primary with 79 percent of the vote. Womack is easily winning the fundraising game and reported having $2 million on hand in mid-February, compared with Penzo’s $66,000. An outside group has been supporting Penzo and tried to paint Womack as a “Republican in Name Only,” with about $9,000 worth of ads and text messages. But in a possible sign the message might have been getting through, a group backing Womack reported on Feb. 1 that it was putting $107,000 into digital ads. Penzo launched his campaign after Womack was one of several Republicans who did not vote for Jim Jordan, a co-founder of the House Freedom Caucus, for speaker in October.