A bloc of Trump voters in key swing states also backs Democratic Senate candidates. Here's why that matters.

• Donald Trump hopes to push several swing-state GOP Senate candidates over the finish line.
• But some of his supporters say they plan to back Democrats in those races instead.
• These split-ticket voters could end up having a major impact on the country.

In recent presidential election cycles, the level of ticket-splitting — where people vote candidates from different parties on their ballot — has plummeted.

Some 20 years ago, then-Democratic presidential nominee John Kerry lost GOP-leaning states like Arkansas and North Dakota even as the incumbent Democratic senators in those states — Blanche Lincoln and Byron Dorgan — coasted to victory.

This sort of ticket-splitting was generally not seen as atypical.

But by 2020, things were different. Maine was the only state that year where voters backed a presidential candidate from one party (Democrat Joe Biden) and a Senate candidate from another party (Republican Susan Collins).

In November, a slew of incumbent Democratic senators are running for reelection in states where the race between Vice President Kamala Harris and former President Donald Trump remains competitive.

However, there's an interesting dynamic at play in pivotal swing states like Arizona, Michigan, and Pennsylvania headed into November: A relatively small but significant bloc of Trump voters are also backing Democratic Senate candidates.

While many of these Trump voters have long been loyal to the former president, many of the Democrats running have more moderate political brands that are — so far — giving them polling advantages over their GOP counterparts.

Here's a look at how pro-Trump ticket-splitters could invariably aid a Harris presidency should she win the general election, or cause trouble for a Trump agenda should he emerge as the victor.

Ahead of the pack

Even before Biden ended his reelection bid, swing-state Democrats running in the most competitive Senate races were generally leading in the polls.

While Biden struggled in his matchup against Trump, many voters earlier this year had already began to differentiate between the presidential race and down-ballot candidates.

Trump has eagerly thrown his support behind GOP Senate candidates like Kari Lake of Arizona, Mike Rogers of Michigan, Bernie Moreno of Ohio, and David McCormick of Pennsylvania. And he's implored his supporters to vote for these candidates.

But Democrats in these races have largely defied the conventional political norms of today.

According to the latest New York Times/Siena College survey of five competitive Senate races, an average of 7% of likely voters indicated they would back Trump while also pulling the lever for a Democratic Senate candidate.

The polled states included Arizona, Michigan, Ohio, Pennsylvania, and Wisconsin.

Of the five states, Ohio is most likely to vote for Trump, as he easily won it in both 2016 and 2020. And the most recent Times/Siena survey showed Trump with a six-point advantage over Harris (50% to 44%) in the Buckeye State among likely voters.

But in that same poll, Democratic Sen. Sherrod Brown had a four-point edge over Moreno among likely voters (47% to 43%). Brown also won over 13% of Republicans in the poll, a level of crossover support that helps him in the red-trending state.

The Times/Siena poll also showed Democratic Rep. Ruben Gallego leading Lake by six points (49% to 43%) in Arizona. In Michigan, Democratic Rep. Elissa Slotkin led Rogers by five points (47% to 42%). And in Pennsylvania and Wisconsin, Sens. Bob Casey Jr. and Tammy Baldwin led their GOP opponents by nine and seven points among likely voters, respectively.

Why does this matter?

Should Democrats run the table in the most competitive swing-state Senate races, it'll leave them on the cusp of holding on to a majority.

For Democrats, winning both safe and swing-state races — along with Ohio — would get the party to 49 seats. Then they'd need Montana Sen. Jon Tester to win reelection to get to 50 seats. (Tester is currently locked in a tough reelection battle against Republican Tim Sheehy in a state that Trump is expected to win by double digits.)

Democrats are now trying to expand their Senate map by investing more money in Florida and Texas, which lean Republican on the presidential level but are poised to have close Senate races.

Holding a majority is the best-case scenario for Harris should she win the election, as she would need a Democratic-led Senate to not only move through most of her agenda but also approve the bulk of her judicial appointments.

If Harris wins in November and Democrats win exactly 50 seats, then Minnesota Gov. Tim Walz would deliver a majority by virtue of the vice-presidential tie-breaking abilities.

And Democrats would be able to thank some of Trump's voters for that.

But should Trump win the election and pro-Trump ticket-splitters help Democrats keep their majority, it would pump the brakes on a conservative agenda.

A Democratic Senate would serve as a check on Trump. If Democrats flip the House, that chamber would be another check on him. And even if Republicans keep the House in a potential Trump second term, they'd clash with a Democratic-led Senate on a range of issues.

So ticket-splitters who are backing Trump now have the potential to become one of the most important voting blocs of the 2024 election.