A weird thing about Senate elections is that it’s often based on circumstances from earlier cycles, with some incumbents benefitting from earlier wave years. Republicans had decent years in 2010 and 2016, which meant they were defending 60 percent of seats in 2022 (still no excuse for awful candidates in Arizona, Pennsylvania and Georgia.) The class of 2024 comes after strong Democratic cycles in 2006, 2012 and 2018.
Looking at the states up in 2024, this is how I see the landscape.
Democrats heavily favored to keep a seat
California- Whether it’s an open election, or whoever is appointed to replace Dianne Feinstein is running for a full term.
Republicans heavily favored to keep a seat
Nebraska (Special Election)- Ben Sasse is retiring, but this is a state Republicans win by around 20 points.
Democrats favored to keep a seat
Maine- Angus King is an independent who caucuses with Democrats. He will run for a third term at 80, and even if he changes his mind, an open election in Maine favors Democrats.
Michigan- It’s a swing state where a Republican came within two points of unseating an incumbent in 2020, although Stabenow seems like a stronger incumbent.
New Mexico- It’s a bit more competitive than New York or Maryland.
Pennsylvania- It’s a swing state, although the incumbent is popular.
Virginia- The popular Republican Governor defeated a former Democratic Governor, so Republicans have a shot with a good nominee.
Wisconsin- It’s a swing state, although the incumbent is popular.
Republicans favored to keep a seat
Florida- It’s more of a red state than a swing state now.
Indiana- Open election
Texas- Ted Cruz did win by only three points last time.
Democrats hold a really competitive seat
Arizona- Sinema essentially counts as a Democrat here, but this was going to be a competitive seat whether she officially stayed in the party or not.
Montana- Incumbent holds seat in state Trump won by 16 points.
Nevada- The incumbent Democratic Governor lost. The incumbent Democratic Senator won narrowly.
Ohio- Incumbent holds seat in increasingly red state.
West Virginia- Incumbent holds seat in state Trump won by nearly 40 points.
Republicans hold a really competitive seat
This may be why there’s some talk about whether Sotomayor (a 68 year old with a major health condition) should leave the court. It’s entirely possible that after 2024, there won’t be the combination of a Democratic President and Senate for some time.
Much is unpredictable. There could easily be a Democratic wave year, especially if Republicans nominate Trump, or if he loses the nomination and torches the party. Politicians can have scandals, and lose sure things. Strong candidates can make a difference, as can weak candidates.