The five most important Senate races to watch in 2024

In less than two weeks, the 2024 presidential election will begin with the Republican convention in Iowa. Former President Donald Trump will likely dominate the heavily white, church-going state. Meanwhile, President Joe Biden faces no legitimate challenge in the Democratic primary despite concerns about his age and low approval numbers.

But just as important as who wins the White House will be the makeup of the Senate, which will determine the types of cabinet and judicial nominees who can be confirmed.

In 2022, Democrats avoided the worst possible outcome when they held all the Senate seats, and Senator John Fetterman flipped the Pennsylvania Senate seat for them, giving them a 51-seat majority. Republicans, for their part, have fielded a number of unelectable candidates, many of whom won their primaries thanks to Mr. Trump's support.

This time is different. Democrats are defending Senate races in eight swing states. Three of them — Montana, West Virginia and Ohio — are ones Trump won twice. Another four — Arizona, Pennsylvania, Wisconsin and Michigan — are in states he won in 2016 but lost in 2020. Another takes place in the perennial state of Nevada. This means that even if Democrats won races in all states won by Biden in 2020 and Republicans won all states won by Trump, Republicans would still control the Senate by three seats.

In 2022, Inside Washington regularly publishes lists of the top five Senate races. Since West Virginia will almost certainly change, we're changing the format to show you the most important Senate races to watch. Here are your five races that will determine the balance of the Senate.

1. West Virginia

There is no other way around it. Sen. Joe Manchin's (D-WV) decision not to seek re-election — and possibly join a quixotic third-party bid for president — means he will likely be the last Democrat elected from the heavily white state based on largely in the coal industry for at least a generation. After years of beating the odds by selling himself as a different kind of Democrat, Mr. Manchin's luck ran out after he authored the Lower Inflation Act, a massive bill focused on climate change and health care. Biden signing the law meant he could no longer differentiate himself from the rest of the party. Republicans got the nominee they wanted when Gov. Jim Justice — Mr. Manchin's former friend who switched parties thanks in part to Mr. Trump — announced last year that he would run. This will be the last time this list mentions West Virginia since Mr. Justice will almost certainly become the next senator from the Mountain State.

2. Ohio

Mr. Manchin's withdrawal means Republicans will target the other two Democrats in a state Trump won twice. Sen. Sherrod Brown (D-OH), a populist Democrat who used his seat on the Senate Banking Committee to criticize Wall Street, has been largely fortunate to have run in good years for Democrats like 2006; in 2012 and 2018. Mr. Trump won Ohio by eight points in 2020, meaning that Mr. Trump would need to simultaneously underperform in Ohio and Brown to outperform. Right now, the Republican field is split with multiple candidates, including Secretary of State Frank LaRose, state Sen. Matt Dolan and businessman Bernie Moreno. Last month, Mr. Trump endorsed Mr. Moreno, a conservative who was endorsed by Senator JD Vance. On Wednesday, the political action arm of the conservative Development Club also endorsed Mr. Moreno.

3. Montana

In fact, Montana or Ohio could switch places on this list. In fact, Mr. Trump won mostly rural Montana by double digits. Democratic state Sen. Jon Tester has long positioned himself as a unique Democratic brand thanks to his work as a rancher who lost three fingers in a meat grinder accident and as chairman of the Senate Veterans Affairs Committee. But his polling rate is more liberal than Mr. Manchin's. He has pulled off miracles in the past, including in 2012 when he won re-election despite Mitt Romney winning the state and in 2018 despite voting against the confirmation of Brett Kavanaugh to the Supreme Court. But it can be harder to get around. The only thing he wants is his opponents. Rep. Matt Rosendale, an archconservative who won in 2018, has floated the idea of ​​running against Tim Sheehy, a retired Navy SEAL pilot backed by the GOP establishment. A bloody primary could result in Mr. Rosendale's victory or Mr. Sheehy's significant weakening.

4. Arizona

Arizona is shaping up to be perhaps the strangest Senate race in the country. In 2018, Kyrsten Sinema became the first Democrat to win a Senate race in Arizona in 30 years. In the years that followed, she regularly opposed her party's legislation or blocked filibuster changes to pass voting rights. After Sen. Raphael Warnock (D-GA) won the 2022 runoff, he announced he would leave the Democratic Party to become an independent, though he would still caucus with Democrats. Ms. Sinema has not announced whether she will seek re-election, but Rep. Ruben Gallego (D-AZ), an outspoken Latino progressive and retired Marine, has announced that he will challenge her. On the Republican side, Carrie Lake, the former news anchor who lost her bid for governor in 2022 thanks to her continued election refusal, announced she would run for the seat. If it were a three-way race, Ms Sinema would likely draw votes from Ms Lake rather than Mr Gallego. But too much is unclear until Ms. Cinema makes up her mind.

5. Nevada

Like Arizona, Nevada will likely be one of four states to decide the presidency, along with Wisconsin and Georgia. In 2018, Sen. Jackie Rosen beat incumbent Republican Dean Heller in the Silver State thanks to a powerful Democratic machine led by the late Senate Majority Leader Harry Reid. But even as Democrats have won the state in every election since 2008, their margins have narrowed significantly. Additionally, Sen. Catherine Cortez Masto, the Senate's lone Latina, narrowly won re-election in 2022, even as Republicans won back the governorship. So far, Republicans have largely backed veteran Sam Brown, while, as friend of the newsletter Gabby Birenbaum The Nevada Independent flag Last month, Sen. Tommy Tuberville of Alabama held a fundraiser for election denialist and failed Secretary of State Jim Marchant at Mar-a-Lago. Nevada is known for tight Senate races (the late Mr. Reed lost his first Senate race by 624 votes and won another term by 401 votes). And the rightward shift of Latino voters is helping Republicans. But anger at the Supreme Court Dobbs v Jackson The decision could push Ms. Rosen as it did Ms. Cortez Masto.