By Jonathan Weisman
The fight for Senate control is playing out almost entirely in Democrat-held seats this year as President Joe Biden’s party defends a slim 51-49 seat majority.
The retirement of Sen. Joe Manchin, a Democrat, in deep-red West Virginia has all but ceded one seat to the Republicans, who are targeting a number of vulnerable Democratic incumbents in red or swing states. And if former President Donald Trump wins the White House, one seat is all the GOP needs to flip the chamber. Should the Senate come down to a 50-50 split, the vice president plays tiebreaker.
For Democrats to hold the Senate, the party would most likely need all their incumbents to win; for their candidates to prevail in open seats in Arizona, Michigan and Maryland; and for Biden to be reelected so Vice President Kamala Harris would play the tiebreaker in an evenly split chamber. The party is targeting two Republican-held seats, but those are considered more difficult terrain.
Here are the Senate races to watch in 2024.
Montana: Farmer vs. former Navy SEAL
Sen. Jon Tester, the flat-topped farmer from Big Sandy, Montana, has defied the odds before in his increasingly Republican state, but his Senate victories in 2006, 2012 and 2018 all came in strong Democratic years nationally. His fight for a fourth term will be considerably tougher with Biden at the top of the ticket in a state that Trump won by 16 percentage points in 2020. And Tester will most likely be battling the Republican Party’s selected candidate, Tim Sheehy, a decorated former Navy SEAL and businessperson with the wealth to self-finance his campaign, as well as Trump’s backing.
Tester has the power of incumbency and the authenticity of a third-generation Montanan. In 2012, President Barack Obama received 41.7% of the vote. Tester earned 48.6%. He may need even more ticket-splitters — people who will vote for Trump for president and him for Senate — this November.
Cook Political Report rating: A toss-up
Ohio: Sherrod Brown faces the fight of his political life
Besides Tester, Sen. Sherrod Brown is the only other Democrat defending a seat in a solidly Republican state. He, too, has had the advantage of winning in strong Democratic years — 2006, 2012 and 2018 — and like Tester, he has established an image as a stalwart supporter of the working-class voters who will decide the election. As a powerful member of the Senate — he is the chair of the Senate Banking Committee — Brown has amassed a considerable war chest for his reelection campaign.
Unlike Tester, he will be running against a Republican who was not the Ohio GOP establishment’s choice. Bernie Moreno, instead, was the candidate of Trump. The Republican’s sizable fortune will seed fundraising and undergird his campaign against the incumbent, but Democrats boosted Moreno’s candidacy during the primary because they believe his business background will make him vulnerable to attack.
Cook Political Report rating: A toss-up
Arizona: Kari Lake, a prominent election denier, tries again
The retirement of Sen. Kyrsten Sinema, the Democrat-turned-independent iconoclast, has set up a stark Senate race between Rep. Ruben Gallego, a progressive, and Kari Lake, a former television news anchor and a favorite of Trump’s Make America Great Again movement who lost her race for governor in 2022. The primary in Arizona is July 30, but Gallego and Lake have established themselves as the odds-on favorites to represent their parties in the open Senate contest.
Biden narrowly won Arizona in 2020, and unlike Ohio and Montana, the state promises to be a presidential battleground, potentially warping the Senate race. Lake made a name for herself by falsely claiming that Democrats stole the Arizona election for Biden in 2020, then falsely claiming that her Democratic opponent in the governor’s race, Katie Hobbs, stole her election. Gallego is less well-known outside his Phoenix House district, but as a Latino with a Harvard pedigree and combat experience in Iraq with the Marine Corps, he has a compelling biography.
Cook Political Report rating: A toss-up
Michigan: Trump looms large
The full range of Republican Party factions will fight it out for the right to contend for the Senate seat of Sen. Debbie Stabenow, a Democrat who is retiring. There’s Peter Meijer, who voted to impeach Trump just after being sworn into the House, then lost in the 2022 Republican primary to a Trump-backed challenger. Meijer has now said he will vote for Trump in November. There’s Justin Amash, the libertarian-minded former congressman who denounced Trump, faced a fierce backlash that chased him from his party, tried to run for his House seat as an independent, lost and is now running for the Senate again as an anti-Trump Republican. Then there’s Mike Rogers, the mainstream Republican who said the party needed to move on from Trump, then wooed and won Trump’s endorsement for Senate and embraced him.
Rogers has to be considered the favorite in the Aug. 6 primary, but past and present views of the former president will loom over this race all summer. The primary winner will almost certainly face Rep. Elissa Slotkin, a Democrat who has used her national security credentials to win over swing voters in central Michigan since 2018. Her trick will be to keep those centrist voters and energize more liberal voters in and around Detroit. And looming above it all is the presidential contest.
Cook Political Report rating: Leaning toward Democrats
Nevada: Low-key incumbent vs. political newcomer
In recent years, Nevada Democrats have profited off Republican voters’ penchant for nominating candidates from the GOP’s extremes, but this year, party leaders are rallying around Sam Brown, a political neophyte with an extraordinary story. The West Point graduate nearly died in Kandahar, Afghanistan, when a roadside bomb burned him badly and left him permanently scarred. His thin political resume could be a plus, since it will make him difficult to label.
Sen. Jacky Rosen, the incumbent Democrat, isn’t flashy, but the power of incumbency matters, unless Biden’s support in the state craters.
Cook Political Report rating: Leaning toward Democrats
Wisconsin: A wealthy Republican candidate faces questions over his ties to the state
Sen. Tammy Baldwin, a Democrat, has been a low-key fixture in Wisconsin politics since her election to the state Assembly in 1992. With her comes little drama, but Wisconsin, a state that just reelected its famously quiet governor, Tony Evers, in 2022, seems to like Democrats who speak softly.
Republicans have recruited Eric Hovde, a banker and businessperson who, if nothing else, can finance his own campaign. But his connections to Southern California in a state full of Badger pride have helped keep this race leaning toward the incumbent.
Cook Political Report rating: Leaning toward Democrats
Pennsylvania: David McCormick tries again
The Keystone State may be a key battleground in the presidential election this year, but Sen. Bob Casey, the Democratic incumbent, is an institution. His expected Republican opponent is David McCormick, the former CEO of Bridgewater Associates, one of the largest hedge funds in the world. McCormick lost the Republican Senate primary in 2022 to Mehmet Oz, and the lines of attack honed two years ago on his wealth and his mansion in Connecticut are sure to be recycled.
Cook Political Report rating: Leaning toward Democrats
Maryland: Larry Hogan makes things interesting
Reliably blue Maryland should not be in play, but Larry Hogan, the moderate former Republican governor, has decided to run for the Senate seat of Ben Cardin, the retiring Democrat, making the race one to watch.
Democrats had figured they could count on the three-term Rep. David Trone, the wealthy founder of Total Wine & More, a large retailer of wine and spirits. Then Trone used a racial slur at a House hearing, for which he has apologized and said was inadvertent. But several Black Democrats endorsed Angela Alsobrooks, the Prince George’s County executive, before the May 14 primary, as did Rep. Jamie Raskin of Maryland, the top Democrat on the powerful House Oversight Committee.
Cook Political Report rating: Likely Democratic
Texas and Florida: Democrats try to flip seats in reliably red states
Democrats have only two races to play offense in: Sen. Ted Cruz’s campaign in Texas and Sen. Rick Scott’s in Florida. Both men have never been personally popular in their states, but those states have been reliably Republican of late. Democrats like their candidates, Rep. Colin Allred in Texas and former Rep. Debbie Mucarsel-Powell in Florida, but it would most likely take severe erosion of Trump’s support to put those Senate seats in play.
Cook Political Report ratings: Likely Republican