(CN) — Five, 10, and even 15% or more of swing-state voters are telling pollsters that they plan to support Donald Trump for president and a Democrat for the U.S. Senate this November, making the battle for control of the country's upper chamber a nail-biter.
Around the country, “we’re seeing a rebound of ticket-splitting,” said David Macdonald, a political science professor at the University of Florida.
Divided loyalties on the ballot were common 50 years ago, but they all but died out in the last few elections. Their sudden comeback is giving Republican congressional hopefuls heartburn.
On paper, winning back the Senate should be a cakewalk for the GOP this year: The party is defending only 11 relatively safe seats while the Democrats have to defend 23 seats, many of them in red or purple states, at a time when their presidential standard-bearer is struggling.
And yet, thanks to ticket-splitters, Democratic Senate candidates are ahead in almost all of their races — sometimes polling dramatically better than President Joe Biden.
“It’s important to remember that not all Trump voters are alike,” Macdonald said. “Some of them vote for Trump enthusiastically while wearing a hat, but others vote reluctantly while holding their nose.”
Back in the 1970s, it wasn’t unusual for 25% or more of voters to split their tickets, according to Andrew Smith, director of the University of New Hampshire Survey Center. In both the 1972 and 1984 elections, Democrats picked up two seats in the Senate even though Republicans won the presidency in a 49-state landslide. As late as 1996, Democratic President Bill Clinton easily won reelection while Republicans added two Senate seats.
In fact, from 1968 to 2000, at least 10 states in every election backed presidential and Senate candidates of different parties. But this phenomenon didn’t happen anywhere in 2016, suggesting a dramatic hardening of partisanship. In 2020 it happened in only one state: Maine, which voted for Biden but gave a fifth Senate term to Susan Collins — one of the country’s most liberal Republicans.
If the current polls are to be believed, though, 2024 could once again see a raft of states opt for strange bedfellows.
Nowhere is the difference starker than in Montana, where polls show Democratic Senator Jon Tester with a lead of between 2 and 9 points even though Biden is losing the state by 21, according to RealClearPolitics.
In Ohio, Democratic Senator Sherrod Brown is up by 5 points, even though Biden is down by 10.
And the pattern is repeating in other swing states. In Arizona and Nevada, the averages show Democratic Senate candidates Ruben Gallego and Jacky Rosen ahead by 5 points, while Biden trails in both states by 3 or more. In Pennsylvania, Democrat Bob Casey leads his Senate race by 5 points while Biden trails by 3 points. In Wisconsin, Biden and Trump are tied, but incumbent Democratic Senator Tammy Baldwin is leading Republican businessman Eric Hovde by 8 points.
This is a dramatic contrast to 2020, when only 3% of voters split their ticket between presidential and congressional candidates, according to Shiro Kuriwaki, a Yale University professor who wrote his dissertation on ticket-splitting. “That’s the lowest number since surveys began in the 1950s,” he said.
In the past, political scientists have had two theories to explain ticket-splitting, according to Macdonald. One is that voters want divided government in order to balance extreme tendencies. In 1996, for instance, some Republican congressional candidates explicitly made the argument that Clinton would likely be reelected and a Republican Congress was needed to keep him in check.
Under this theory, large numbers of voters want to fire Biden this year, but they are wary of Trump’s potential extremism and want a Democratic Congress as an insurance policy to rein him in.