George Caldwell @GCaldwell_news

[ George Caldwell is a journalism fellow at The Daily Signal.]

Sen. Thom Tillis announced Sunday that he would not be seeking reelection, just one day after President Donald Trump threatened to support a primary challenger against the North Carolina Republican owing to his vote against proceeding with the One Big Beautiful Bill Act.

There could be major implications for Republicans— with a possibility of losing the maverick centrist senator’s North Carolina seat in 2026.

Tillis’ announcement came after Trump was enraged by his vote against a motion to proceed on the 10-year fiscal package.

“Numerous people have come forward wanting to run in the primary against Senator Thom Tillis,” Trump wrote Saturday night.

“I will be meeting with them over the coming weeks, looking for someone who will properly represent the Great People of North Carolina and, so importantly, the United States of America.”

Tillis voted against proceeding with the bill because of his opposition to lowering the provider tax, a tool states use to compel the federal government to provide more funding for Medicaid.

The next day, Tillis lamented “political theatre and partisan gridlock” as he announced his intent to retire at the end of his term late next year.

Tillis has been willing to cooperate with Democrats in the past, lending his support to “red flag” gun control laws and the Respect for Marriage Act, which codified federal recognition of same-sex marriage.

Senate Majority Leader John Thune, R-S.D., said Sunday that the announcement was a long time coming.

“It’s unfortunate, and it’s something he’s been thinking about for a while, and he just finally decided that was the best decision for him and his family,” said Thune.

Tillis’ departure is emblematic of a larger trend within the Republican Party as centrists become more rare and others coalesce around Trump.

Rep. Don Bacon, R-Neb., who has not been shy about criticizing Trump on occasion, also announced over the weekend that he would not be seeking reelection in his purple swing district in 2026.

A Political Earthquake Now, Republicans have to worry about the consequences of losing Tillis in North Carolina, a key swing state where he has strong name recognition from his years as speaker of the state House of Representatives before becoming a U.S. senator.

Tillis already had his operation up and running, having hired longtime Trump pollster Tony Fabrizio for the campaign, which Cook Political Report has just shifted from “Lean Republican” to “Toss Up” in its projections.

That could spell trouble, as Democrats are also eyeing Senate pickup opportunities in Maine and Texas in 2026.