The Senate Primaries to Watch So Far

Incumbents have had a lot of primary success lately



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— The Editors


— It has been over a decade since an incumbent senator was successfully primaried in a regularly-scheduled election; though a few senators may be vulnerable, 2024 may continue that streak.

— Sen. Dianne Feinstein’s (D-CA) decision to retire removed one vulnerable senator from the primary conversation; Sen. Kyrsten Sinema’s (I-AZ) decision to leave the Democratic Party removed another. Among the other incumbents who are still deciding whether to run for reelection, Sen. Mitt Romney (R-UT) stands out as someone who could hypothetically be vulnerable in a primary.

— The open-seat Senate contests are all in various stages of flux. Indiana, the sole GOP-held open seat so far, seems to be the most straightforward, as Rep. Jim Banks (R, IN-3) is a heavy favorite to replace Sen. Mike Braun (R-IN).

Checking in on Senate primaries

One of the peculiarities of the 2022 election cycle was that, despite a good deal of political turbulence the past few years, incumbents thrived. Only a single incumbent governor lost (Democrat Steve Sisolak of Nevada), and not a single incumbent senator lost, either in the primary or general elections.

In fact, no sitting senator has lost a primary in any of the last 5 regular elections — they were undefeated for renomination in 2014, 2016, 2018, 2020, and 2022. That ties the 1982-1990 stretch for the longest string of regular elections since World War II where no senator lost a primary, per the Brookings Institution’s Vital Statistics on Congress.

The only incumbent blemish in recent years came in an irregularly-scheduled special election, when appointee Luther Strange (R) lost to Roy Moore (R) in the 2017 Alabama special election primary.

Besides that, the last incumbent senator to lose a primary was way back in the 2012 cycle, when long-serving Sen. Richard Lugar (R-IN) lost to then-state Treasurer Richard Mourdock (R). (Notice that both of the most recent Senate primary defeats saw GOP primary voters swap out a probable general election winner for a loser.)

As we look ahead to the 2024 Senate primary season and ponder whether any incumbent is in jeopardy, it’s worth remembering this history: Incumbent senators are hard to unseat in a primary setting.

Part of what might keep the incumbents’ streak going this cycle is the early decisions by a couple of senators not to pursue renomination next year.

On Tuesday, long-serving Sen. Dianne Feinstein (D-CA) announced her retirement: There have been questions for years about the elderly Feinstein’s capacity to serve, and it appears she is finally bowing to reality. A couple of California House members helped nudge her towards the door by announcing their bids before she announced her plans (more on that below).

Late last year, Sen. Kyrsten Sinema of Arizona left the Democratic Party, opting to become an independent despite continuing to caucus with Democrats. She too would have had trouble in a primary given some high-profile breaks with President Biden and other Democrats over the past few years.

So with those moves, the two senators who might have had the hardest time getting renominated are not running for renomination (or, at least in the case of Feinstein, not running at all — Sinema’s future plans remain a mystery).

So what other primaries merit watching? Let’s go through some others we are monitoring:

— Sen. Mitt Romney (R-UT) has not announced his 2024 plans. During his term, Romney has emerged as a key member of the Senate’s centrist bloc. Romney may have frustrated state partisans last year, as he was not seen as a “team player” — he was the only sitting Republican senator who did not endorse his home-state Sen. Mike Lee (R) for reelection. Lee, who was elected in 2010, actually is the most recent senator who made it to the chamber via a successful primary challenge (remember, Mourdock in 2012 and Moore in 2017 lost). And Lee’s case was special: he defeated the late Sen. Bob Bennett at a convention. Under the rules at the time, Bennett placed third at the May party convention, so he could not advance to the June primary. But under Utah’s current system, Republicans who don’t earn the party’s endorsement at the convention can petition to appear on the primary ballot. In fact, in 2018, Romney placed second at the party convention but went on to easily win with a broader primary electorate.

With Feinstein and Sinema out of the picture, Romney is hypothetically the most vulnerable incumbent in the 2024 primary season (assuming he runs). Bryan Metzger of Insider had a good rundown recently of Romney’s challenges; he quoted an unnamed Utah Republican consultant who said that polling suggested Romney was in the low 40s in a hypothetical primary. That might be enough to win if his opposition is splintered, but Romney may struggle against a single, strong opponent.

— The most recent addition to the Senate has been from Nebraska: after wrapping up 2 terms as governor, Republican Pete Ricketts was appointed to replace fellow Republican Ben Sasse, who began leading the University of Florida earlier this month. Ricketts will run in a special election next year, alongside Sen. Deb Fischer (R-NE), whose seat was already set to be up. We are not expecting Fischer to have much competition in her primary. Fischer is running for a third term despite previously supporting a two-term limit for senators — but many members who did not abide by their own term limit ideals have been reelected anyway.

Ricketts, meanwhile, may have to at least break a sweat in his primary. Businessman Charles Herbster, who was last seen losing the GOP primary for governor last year, is openly considering the race. In the 2022 primary, Ricketts endorsed now-Gov. Jim Pillen over Herbster, who had Donald Trump’s support. One of Pillen’s first acts in office was to appoint Ricketts to the Senate. Ricketts would be the favorite in a primary, although appointed incumbency is not always the same as elected incumbency, and a challenger could try to capitalize on the circumstances of Rickett’s appointment, perhaps by arguing it seemed transactional. Lingering questions over his selection seemed to hurt Luther Strange in his primary. Before Ricketts, Nebraska’s most recent appointed senator, the late Republican Dave Karnes, actually drew a serious primary challenger when he ran in his own right, in 1988. He beat then-Rep. Hal Daub (R, NE-2) by 10 points in the primary, but had the bad fortune of running against Bob Kerrey, a Democrat who was then a popular former governor, in the general election (Kerrey won by 15 points). Democrats do not have a Kerrey-type figure waiting in the wings, so Republicans would still be favored in the general election this time.

— While there is no sign he faces a competitive primary, Sen. Rick Scott (R-FL) was just endorsed by the Club for Growth, which often acts as an anti-establishment force in Republican politics. Following an unsuccessful tenure as chairman of the National Republican Senatorial Committee, Scott failed in a challenge to Senate Minority Leader Mitch McConnell (R-KY) for leadership of the caucus. McConnell has criticized Scott for a plan the latter released during last cycle that included a proposal to force Congress to re-approve federal programs, including popular ones like Social Security and Medicare, every 5 years — a proposal that Democrats, including President Biden in last week’s State of the Union, have highlighted. Scott was recently kicked off of the Senate Commerce Committee — as this was likely a form of retaliation from leadership, Scott has spun it as evidence of his anti-establishment credentials in his fundraising appeals.

— On opposite sides of the Delmarva peninsula, Sens. Tom Carper (D-DE) and Ben Cardin (D-MD) are both mulling whether they will run again. Both would likely be fine in both primary and general elections if they run again, although there also are deep benches in both states that would relish the opportunity to compete for an open seat. It is worth noting that Carper attracted a left-wing challenger in 2018, now-state Rep. Kerri Evelyn Harris. With memories of now-Rep. Alexandria Ocasio-Cortez’s (D, NY-14) upset primary victory over the then-No. 4 House Democrat, Joe Crowley, still fresh, the race generated some attention that summer, but Carper won convincingly with a little less than two-thirds of the vote.

— Speaking of Ocasio-Cortez, she decided to pass on challenging Senate Majority Leader Chuck Schumer (D-NY) in last year’s primary, and there’s not much indication that she or any other Democrat of note would want to challenge Sen. Kirsten Gillibrand (D-NY) this cycle.

— Back in 2018, Sen. Robert Menendez (D-NJ) scored an unimpressive 62%-38% primary victory over a little-known activist, Lisa McCormick (D). This came a year after Menendez survived a federal corruption trial, and Menendez is reportedly under investigation again for a separate matter. Menendez has already drawn a couple of challengers, the more notable of whom is Joe Signorello III (D), the mayor of a small town, Roselle Park.

— Sen. Elizabeth Warren (D-MA) would likely be fine in a primary, although Politico’s Massachusetts Playbook did recently float Reps. Jake Auchincloss (D, MA-4) and Ayanna Pressley (D, MA-7) as possible challengers. Both suggested that they weren’t interested. Massachusetts was the site of a big Senate primary in 2020, when Sen. Ed Markey (D-MA) fended off then-Rep. Joe Kennedy III by a little over 10 points (Auchincloss succeeded Kennedy in the House). With memories of that divisive 2020 primary still fresh in the minds of state Democrats, there simply may not be much appetite for a Warren challenge — as with Markey, she has not committed any obvious partisan apostasies.

— Arizona, an odd situation where Sinema is now an independent who caucuses with Democrats, may be one of the biggest question marks on the map. For at least the last year or so, it has been evident to all observers that Sinema would have a hard path to renomination — a reality that likely prompted her to leave the party. Even though she’s not running for renomination, we thought her race merited mention, too.

Towards the end of last month, Rep. Ruben Gallego (D, AZ-3) got into the race and has fundraised well. Though Gallego may not have the primary field to himself, he has probably been Sinema’s most vocal intra-party critic over the last few years. It seems likely that most Democratic primary voters will at least identify with his frustrations — he is selling buttons that read “Adios Sinema.” Since her switch, Sinema has kept reeling in donations, although if she pursues reelection as an independent, her path to victory would seem narrow. Republican Sen. John Thune (R-SD) has implored Sinema to go further, and actually cross the aisle. But Sinema’s numbers with Republicans are not impressive, so it’s unclear how GOP partisans would react to a Sinema candidacy, especially if more conservative options enter.

It’s early in the cycle, so undoubtedly there will be more primary action involving incumbents to watch. Beyond the races featuring incumbents running for renomination, let’s close by looking at the 3 states that are hosting open-seat primaries:

— Last year, Republicans bungled a seemingly golden opportunity to flip the Senate due in large part to the poor quality of their candidates in key states. But for the 2024 cycle, there are signs that Senate Republican leadership will take more of an active role in the primary process, with the goal of precluding another 2022-style debacle.

Let’s take Indiana as an example. With first-term Sen. Mike Braun (R-IN) forgoing reelection to run for governor, the Hoosier State is the only open GOP-held seat on the map so far. Rep. Jim Banks (R, IN-3), who has represented the Fort Wayne area for 4 terms in Congress, announced his bid for Braun’s seat in mid-January. When former Gov. Mitch Daniels (R-IN), who had been toying with the idea of a Senate run, passed on a run, the NRSC almost immediately threw its weight behind Banks. The NRSC’s endorsement may have also deterred some other Republicans from entering the race — most notably, Rep. Victoria Spartz (R, IN-5) was reportedly exploring a 2024 statewide run, but she (surprisingly) opted to retire from office altogether. So, with these early-cycle developments, Indiana’s open-seat race seems to be a coronation for Banks.

Indiana is a state that Republicans will probably win by double-digits at the presidential level, and we expect our Safe Republican rating for the Senate contest would have applied even if the outlook for the primary was messier. But, using Indiana as a template, it seems that this cycle’s NRSC wants to leave as little to chance as possible.

— If the Indiana seat seems settled, Michigan’s contest still seems relatively fluid. Since Sen. Debbie Stabenow’s (D-MI) retirement announcement last month, no major candidates have officially jumped in, although several are reportedly considering. We explored the dynamics of that race a bit more last month.

— Even before Feinstein announced her retirement Tuesday, Democrats from the state’s House delegation weren’t waiting for her to step aside. Two Southern California Democrats, Reps. Adam Schiff (D, CA-30) and Katie Porter (D, CA-47), were already running, and Rep. Barbara Lee (D, CA-12), who represents Oakland, has reportedly been preparing to enter the race. Though Schiff, Porter, and Lee each have their own followings, it’s important to remember that, as members from the House’s largest delegation, they only represent small pieces of the state. State senators in California actually have more constituents than U.S. House members do — there are 52 of the latter, but just 40 of the former.

Coincidentally, the last time this seat was truly open, way back in 1982, was also a rare contest that featured 3 sitting House members — they all lost the Republican primary to then-San Diego Mayor Pete Wilson. Wilson won in 1982 and 1988 before resigning in 1990 to become governor; Feinstein defeated John Seymour (R), who Wilson appointed to replace him in the Senate, and she has held the seat ever since. One change from 1982, though, will be that the state now uses a top two primary system. With most of the major contenders likely to be Democrats, a pair of Democrats may ultimately face off in November — this was the case in 2016 and 2018.