The Most Vulnerable Senate Seat Just Became a Lot More Vulnerable

On Sunday afternoon, Republican Sen. Thom Tillis announced that he would no longer seek reelection to the seat that he has held since 2014. In so doing the Senate seat most vulnerable to flipping to the other side became even hard for Republicans to hold. (The next two seats are Democratic-held Georgia and Republican-held Maine, followed by a rather precipitous drop-off to the next tier of seats.)

To be sure, Tillis was in a precarious position to begin with. I’ll talk about the political leanings of the state below, but for now I’ll just assert this is a narrowly divided state. This requires Tillis to walk a tightrope of supporting the Republican president enough not to lose his base, but opposing him enough to keep moderates on board.

This has become increasingly difficult in Trump’s second term, especially as MAGA commentators have increasingly taken a stance that opposing any of the president’s agenda is unacceptable. Tillis, for example, drew heavy fire for opposing Trump’s nominee for United States attorney for the District of Columbia. His retirement appears to be precipitated by a salvo of attacks from the president after Tillis voted “no” on a procedural vote to advance the “Big, Beautiful Bill.”

At the same time, Tillis faced a general election that already likely tilted away from him. His primary concern was former Gov. Roy Cooper. Cooper was never the biggest vote-getter in North Carolina history, but he was a reasonably popular figure in the state. If Cooper failed to get in, the conventional wisdom is that Attorney General Jeff Jackson was waiting to take the plunge. Jackson, while definitely quite liberal, is great on the stump and generates a ton of energy from his supporters. He would be a formidable general election candidate as well. In the absence of those two, Wiley Nickel, former congressman from the 13th Congressional District, is at least a “generic Democrat.”

With Tillis out, Republicans lose the benefit of incumbency. In addition, Republicans face the prospect of a messy primary, with the possibility that a radioactive candidate, such as former Lt. Gov. Mark Robinson, might emerge. We might laugh, but bad Republican candidates have probably cost the party half a dozen seats in the current Senate. The much-discussed front-runner at this point, Lara Trump, might have been a good candidate in a Trump-friendly year like 2024, but at this point at least, 2026 looks different.

Against this background, the rejoinder is that North Carolina functions somewhat like Pennsylvania did for Republicans for quite some time: Lucy’s football to Charlie Brown. Democrats have won exactly zero federal races since Barack Obama narrowly carried the state in 2008 and Kay Hagan defeated Sen. Elizabeth Dole in the same year.

But …

Since 2008 Republicans have been fortunate to have only a handful of really bad election years. 2018 was the only “wave”-like environment we’ve witnessed, with 2012 and 2020 standing more as “not great” years for the GOP. The 2022 elections were disappointing, but Republicans still won the popular vote for Congress by 3 points.

Through the vagaries of the calendar, Republicans have only defended one Senate seat in the state in a “bad” or “not great” year for the GOP since 2008: Thom Tillis’ win in 2020. Tillis won that seat by 1.5 percentage points after it came out that his opponent had (at the very least) exchanged sexually explicit texts with a woman who wasn’t his wife.

The other Senate races have all occurred in favorable environments for the GOP: 2010, 2014, 2016, and 2022. Of these, 2010 was the only big win for the Republicans. 2016 was a 6-point win for Sen. Richard Burr, while 2014 and 2022 were low-single digit affairs.

Not only that, but North Carolina has quietly been moving away from Republicans over the past few decades. The state was 3.5 percentage points more Republican than the country as a whole in 2008. By 2020 it shifted to just under 3 points more Republican than the country as a whole. COVID brought an influx of New Yorkers to the state, particularly the Research Triangle Park area; the state was less than a point more Republican than the country overall in 2024.

That would still be enough for a normal Republican to win against a normal Democrat in a neutral year (again, it isn’t clear that we will see either a normal Republican or a normal Democrat this year). But 2026 isn’t shaping up to be a neutral year. To be clear, people badly underestimate how popular Trump is right now – his job approval is just 4 percentage points underwater in the RealClearPolitics Average – but that’s still enough to create an unfavorable environment in a swing state.

Of course, there’s also a lot of time between now and November. We don’t know if Cooper will get in, much less whether Jackson will get in. For now, this seat goes from being vulnerable for Republicans to extremely vulnerable.