There will be 34 U.S. Senate seats on ballots across the nation in November 2024, including 20 held by Democrats, three by independents, and 11 by Republicans.
Of the 20 seats now held by incumbent Democrats, at least eight are in states defined as “competitive” in initial assessments by elections ratings services such as Sabato’s Crystal Ball and Inside Elections, with three Senate Democrats in states won by former President Donald Trump in 2020: West Virginia, Montana, and Ohio.
Of the 11 U.S. Senate seats held by GOP incumbents, all are in states rated as securely red, although Texas, where Sen. Ted Cruz is seeking a third term, is regarded by Inside Elections as a “battleground Republican” state where a Democrat is expected to be competitive. In addition, Sen. Mitt Romney (R-Utah), if he chooses to run, could face a stiff primary challenge.
The three independent Senate incumbents all caucus with the Democrats with two—Sens. Angus King of Maine and Bernie Sanders of Vermont—heavily favored to be reelected (although Sanders hasn’t formally said he will run in 2024).
The third independent, Sen. Kyrsten Sinema of Arizona, elected in 2018 as a Democrat before leaving the party in December 2022, hasn’t announced her 2024 intentions.
If she seeks reelection, the 2024 Arizona U.S. Senate election could be a tight three-way race. A strong field of Democrat and Republican hopefuls are already tossing their hats into primary races in this purple state.
Based solely on those numbers, Republicans might have confidence heading into the 2024 elections that they can gain control of the chamber that’s now led by Democrats 51–49.
While all 11 GOP-held Senate seats appear “safe” or nearly so, as many as nine of the 23 incumbent Democrats and independents could be in for difficult reelections.
Of course, with more than seven months to go before the first presidential primary—some states stage presidential primaries separately from preliminaries for the rest of the election slate—the 2024 campaign season is in its infancy; filing deadlines in some states are still months away.
And, of course, despite the favorable math, Republicans were also projected to take the Senate in the 2022 elections but ended up actually losing a seat, to give Democrats a two-vote cushion in the chamber.
In fact, the past two times this cycle of 34 Senate seats was on the ballot—2012 and 2018—Democrats were also expected to lose seats. They gained two in 2012 and lost two in 2018.
Here are updates on 11 Senate seats likely to generate the most competitive 2024 races.
West Virginia: Mooney–Justice GOP Duel
Sen. Joe Manchin (D-W.Va.) has opposed President Joe Biden’s energy policies and student loan forgiveness, among other White House initiatives, but would likely be an underdog in seeking a third Senate term in a state that Trump won by nearly 40 points in 2020.Manchin, who chairs the Senate Energy and Natural Resources Committee and is rumored to be toying with a third-party presidential run, has told reporters he won’t make up his mind until December, a month before the Jan. 27 candidate filing deadline.
The incumbent Democrat had nearly $10 million in campaign donations on March 31, according to first-quarter financial filings with the Federal Elections Commission (FEC). The second quarter ended June 30 with candidates’ FEC disclosures to be publicly updated by mid-July.
Thus far, one Democrat—community activist Zachary Shrewsbury—has filed as a candidate for the May 14 primary while at least four Republicans are already campaigning, including two heavyweights who could make West Virginia’s GOP Senate primary one of the most competitive and combative in the nation.
In late April, Gov. Jim Justice announced he was running for Manchin’s seat and would challenge House Freedom Caucus member Rep. Alex Mooney (R-W.Va.) in the Republican primary. Optometrist Zane Lawhorn and coal miner Christopher Rose have also filed as candidates for the GOP Senate primary.
A late-May East Carolina University survey showed that Justice had a 40 percent lead over Mooney and was more than 20 percentage points ahead of Manchin in a potential November election.
However, Mooney—who is a cousin of Miami mayor and long shot GOP presidential candidate Francis Suarez—is backed by the Club for Growth, which has pledged $10 million for his campaign, and was endorsed by former President Donald Trump in his 2022 midterm primary victory over fellow Republican Rep. David McKinley.
Arizona: Three-Way Race Possible
Sinema has filed the precursory paperwork to run for a second six-year Senate term but hasn’t announced she will do so. With an April 8 filing deadline for the state’s Aug. 6, 2024, primary, much is in flux in the key battleground state.If Sinema chooses to run, she will be embroiled in what could be a competitive three-way race against strong, well-financed Democrat and Republican candidates.
Rep. Ruben Gallego (D-Ariz.) announced in January that he was running for Sinema’s seat and has already had a fundraiser headlined by former House Speaker Rep. Nancy Pelosi (D-Calif.). His campaign raised more than $3.8 million during the first quarter of 2023—$2.2 million more than Sinema’s campaign reported, although it began the year with $10 million cash on hand.
Andrew Becerra, an engineer, is the only opponent formally filed to challenge Gallego for the Democrat nod with Maricopa County Sheriff Paul Penzone and Tucson Mayor Regina Romero also purportedly pondering runs.
The Republican field is uncertain nearly 10 months before the filing deadline, with Pinal County Sheriff Mark Lamb and former gubernatorial candidate George Nicholson the only two formally announced candidates.
Those considering runs include 2022 GOP gubernatorial candidate Kari Lake, who would likely be endorsed by Trump, former attorney general nominee Abe Hamadeh, Karrin Taylor Robson, who lost 2002’s Republican gubernatorial primary to Lake, businessman Jim Lamon, who lost the 2022 GOP Senate primary, Rep. Andy Biggs (R-Ariz.), and Blake Masters, the Republican nominee for U.S. Senate in 2022.
Republican Former Arizona Gov. Doug Ducey has said that he won’t run for office in 2024. He was lobbied by moderates within the party to run because of his cross-party appeal but has opted not to.
Ohio: Brown Seeing Red
Two-term incumbent Sen. Sherrod Brown (D-Ohio) was among the first Senate incumbents to declare he’d seek reelection in 2024, an early campaign start acknowledging that the purple state that elected him twice by 6 percentage points has gone bright red since he was last on a ballot.As of July 3, he doesn’t face significant Democrat challengers in Ohio’s March 19 primary, but there is a lot of time between now and the February filing deadline. Brown’s campaign reported $3.6 million in campaign money to the FEC at the end of the first quarter.
Three Republicans, including two who ran in the 2022 GOP Senate primary won by now-Sen. J.D. Vance, have declared their candidacies, with others likely to join the fray in a state that Trump won by 8 percentage points in 2020.
Midterm senatorial candidates state Sen. Matt Dolan (R-Chagrin Falls), whose family owns the Cleveland Guardians baseball team, and entrepreneur Bernie Moreno, who has been praised by Trump, have formally filed. Little information is available regarding Joel Mutchler, the third GOP hopeful.
Ohio Secretary of State Frank LaRose is expected to announce this month that he will seek the GOP Senate nod as well. Potential candidate Rep. Warren Davidson (R-Ohio) has announced he will seek reelection to the House rather than run for the Senate.
Montana: Tester Seeks Fourth Term
Third-generation rancher Sen. Jon Tester (D-Mont.) has managed to be elected three times as a Democrat in deep-red Montana. In fact, the state’s dominant Republican voters have sent 14 Democrats to the Senate compared with just five Republicans since 1900.Democrats are likely happy that Tester has opted to seek a fourth term with more than $5 million in funds already larding his campaign at the end of 2023’s first quarter.
There are similarities between Tester and Manchin. Like the West Virginia Democrat, Tester has gone against his party and the Biden administration in key votes, including the GOP resolution to eliminate the White House’s proposed ESG investing rule, which the president vetoed.
Thus far, no other Democrats have filed for the June 4, 2024, primary. Two Republicans have tossed their hats into the ring in a field expected to grow before the March 11, 2024, filing deadline.
Retired Navy SEAL Tim Sheehy, a businessman with enough money to self-fund his campaign, is the chosen candidate of Montana’s other U.S. Senator, Steve Daines, who chairs the National Republican Senatorial Committee. Thomas Madigan, who lost a 2022 Montana State House bid, is also signed on to run.
Among other potential Republican candidates are Gov. Greg Gianforte, state Attorney General Austin Knudsen, and Montana’s two congressional representatives: Matt Rosendale, who lost to Tester in 2018, and Ryan Zinke, Trump’s first secretary of the interior.
Pennsylvania: GOP Gears Up to Take Down Casey
Sen. Robert Casey (D-Pa.), the son of former Pennsylvania Gov. Robert P. Casey Sr. and the longest-serving Democratic U.S. senator in Pennsylvania history, has said he will seek a fourth term.Thus far, he faces no opposition within his party for the tentatively scheduled April 23, 2024, primary. The state legislature hasn’t yet confirmed the primary date nor set the filing deadline for 2024 campaigns.
Pennsylvania is considered to be a purple state at the federal level, especially since the 2020 presidential election, when Biden carried the Keystone State by 1.2 percentage points and Sen. John Fetterman (D-Pa.) defeated the GOP’s Mehmet Oz in 2022 to succeed the retired Sen. Pat Toomey (R-Pa.).
As of July 3, only one little-known Republican candidate, Cory Widmann, had filed to challenge Casey, with failed 2022 gubernatorial candidate Doug Mastriano declaring he would not run for the Senate in 2024.
The GOP field, however, is certain to grow with state and national Republican organizations lobbying hedge fund executive Dave McCormick to throw his hat in the ring.
McCormick lost the 2022 GOP Senate primary, his first attempt to run for office, to Oz. Other potential candidates include State Treasurer Stacy Garrity, former Rep. Keith Rothfus (R-Pa.), former U.S. Ambassador to Denmark and 2022 Senate candidate Carla Sands, and Oz.
Nevada: Many Pondering Rosen Run
In another purple state that featured one of 2022’s closest Senate battles, won by incumbent Democrat Sen. Catherine Cortez Masto (D-Nevada) over challenger Paul Laxalt, Sen. Jacky Rosen (D-Nevada) has announced she will seek a second term in 2024.Biden carried Nevada by about 2 percentage points in the 2022 midterms that saw Cortez Masto and all four of the state’s incumbent House representatives, including three Las Vegas area Democrats, reelected while Republican Joe Lombardo was elected governor.
Rosen is seeking a second term after defeating incumbent Republican Sen. Dean Heller by 5 percentage points in 2018. All elections rating services indicate her reelection will be a competitive campaign against whatever Republican emerges from a still coalescing GOP primary field.
Nevada is among the first presidential primary states, with the preliminary inter-party nomination round set for Feb. 6. The primary for the remainder of the electoral slate is June 11, 2024, with March 15 the deadline for candidates to file.
As of July 3, three already have—former state legislator and America First Secretary of State Coalition founder Jim Marchant, who was defeated in his 2022 Secretary of State bid, civil rights attorney Ronda Kennedy, and real estate broker Stephanie Phillips.
Laxalt has declared that he will not run for Rosen’s seat after losing to Castro Masto in 2022, but many other midterm Republican candidates are likely to reappear on ballots in 2024.
Among others considering entering the race are Sam Brown, whom Laxalt edged in their 2022 GOP Senatorial primary; attorney Joey Gilbert, whom Lombardo defeated in their 2022 GOP gubernatorial primary; former U.S. Ambassador to Iceland Jeffrey Ross Gunter; Rick Harrison, a businessman and reality television personality; and Nevada Senate Minority Leader Sen. Heidi Gansert.
Also pondering a run are former Nevada U.S. Reps. Cresent Hardy and Joe Heck, the former two-term Sen. Heller, former Lt. Gov. Brian Krolickl, Douglas County Commissioner Danny Tarkanian, and venture capitalist Guy Nohra.
Michigan: Stabenow’s Retirement Opens Doors
Democratic Sen. Debbie Stabenow is not seeking a fifth term, leaving her seat wide open in this hotly contested purple state that will be a prime GOP target in 2024.Rep. Elissa Slotkin (D-Mich.) has declared her intent to succeed Stabenow and is the clear favorite to win the primary—which has not been formally set, although the presidential primary has been scheduled for Feb. 27. There is, as yet, no filing deadline for candidates.
After declaring her candidacy in January, Slotkin raised more than $3 million in the first quarter of 2023. Attorney Zack Burns, former state lawmaker Leslie Love, and Michigan State Board of Education President Pamela Pugh are among other Democratic challengers.
Republicans who have filed to challenge Slotkin in running for Stabenow’s seat include Michigan State Board of Education member Nikki Snyder, former Dow Chemical Co. executive Michael Hoover, and attorney Alexandria Taylor.
Among those purportedly pondering a run are former U.S. Rep. Peter Meijer (R-Mich.), whose impeachment vote against Trump led to his reelection defeat in the 2022 primaries, businessman Kevin Rinke, former Detroit Police Chief James Craig, and John James, who lost by slightly more than 1 percentage point to Sen. Gary Peters (D-Mich.) in 2020.
Wisconsin: Democrat Incumbent Tough to Beat
Sen. Tammy Baldwin (D-Wis.) is seeking a third term in a purple state where nail-biters are standard, with 2024 likely to stay true to form.With more than $4 million in her campaign chest before even declaring she was running for reelection in April, Baldwin faces no Democratic challengers or Republican opponents as of July 3.
But, of course, that is likely to change soon. The state’s presidential primary is set for April 12, but no date has yet been set for the remainder of the primary slate, although an August date is likely. A filing deadline has also not been set.
Republicans were disappointed when Rep. Mike Gallagher (R-Wisc.) said he would seek reelection in the House, where he chairs the Select Committee on the Chinese Communist Party, rather than run for the Senate in 2024.
Prospective GOP candidates reportedly considering taking on Baldwin include Rep. Tom Tiffany (R-Wisc.), Eric Hovde, a former hedge fund manager who has said he’d commit up to $20 million of his own money if he opts to run, staffing executive Scott Mayer, who said he’ll issue a decision after Labor Day; and former Milwaukee County Sheriff David Clarke.
Texas: Cruz Could Face Another Stiff Challenge
Two-term Republican incumbent Sen. Ted Cruz survived an unexpectedly competitive challenge by Beto O’Rourke in 2018, winning by less than 3 percentage points after winning his first Senate election by more than 15 points in 2012.He could face another one in 2024 with Rep. Colin Allred (D-Texas) announcing in May he was running for Cruz’s seat. A former NFL linebacker, Allred ended the first quarter with more than $2 million in his war chest.
Allred himself may need to survive a rugged Democrat primary with at least six others in the race and state Sen. Roland Gutierrez (D-Uvalde), who would run a strong campaign, set to soon announce his candidacy.
The deadline for candidates to file for Texas’s March 5, 2024, primary is Dec. 11, 2023.
At least two Republicans have signed on to challenge Cruz in the GOP preliminaries. Farmer Josiah Ingalls and former Corpus Christi Mayor Dan McQueen are running for his seat. Rep. Dan Crenshaw (R-Texas) has opted not to run for the Senate in 2024.
Utah: Romney on the Rocks?
Some say Sen. Mitt Romney (R-Utah), the former governor of Massachusetts and the GOP’s 2012 presidential nominee who was easily elected as Utah’s junior senator in 2018, could be vulnerable because of his criticisms of and veto votes against Trump.As of July 3, he faces only one confirmed GOP challenger, Riverton Mayor Trent Staggs, in Utah’s tentatively scheduled June 25, 2024, state primary—March 5 is slated as the state’s presidential primary—but a filing deadline has not been set and there are many potential candidates considering their odds.
Among them is state Sen. Mike Kennedy, who lost to Romney in 2018, state Attorney General Sean Reyes, who has opened eyes across the country in supporting fellow Republican candidates, and data architect Gabriel Lobo-Blanco, who has filed precursor campaign paperwork.
Many other familiar names in Utah and nationwide are purportedly considering challenging Romney in the GOP primary, including former Utah House Speaker Brad Wilson; former four-term U.S. Rep. Jason Chaffetz (R-Utah); Robert O'Brien, a former U.S. national security adviser in the Trump administration; former Utah Republican Party chair Thomas Wright; three-term U.S. Rep. John Curtis (R-Utah); and six-term U.S. Rep. Chris Stewart (R-Utah), who has announced he isn’t seeking reelection to the House but hasn’t indicated whether he plans to run for the Senate in 2024.
California: A Likely All-Democrat Election
With five-term Democratic incumbent Sen. Dianne Feinstein (D-Calif.) announcing she will not run for reelection in 2024, deep blue California’s March 5 Democratic primary could prove to be among the most competitive and expensive 2024 Senate battles.Three Democratic Congressional veterans are already signed on to try to succeed Feinstein: U.S. Reps. Barbara Lee, Katie Porter, and Adam B. Schiff.
Under the state’s ranked voting system, all candidates run in the same primary, meaning it’s likely that the last two standing on November’s ballot will likely both be Democrats.
