WASHINGTON—Centrist Sen. Thom Tillis (R., N.C.) said he won’t seek re-election in 2026, less than 24 hours after he voted against a motion to advance President Trump’s tax and spending megabill, drawing public backlash from the president.

Republican Sen. Thom Tillis of North Carolina announced Sunday he is not seeking reelection next year, a day after he was one of only two Republicans who voted against advancing President Donald Trump’s sweeping agenda bill.

North Carolina Sen. Thom Tillis will not seek reelection after President Donald Trump threatened to seek and support a primary challenger.