Tillis, who is up for re-election next year in battleground North Carolina, voted against advancing a bill for Trump's domestic policy agenda Saturday evening.

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.

The announcement comes a day after President Donald Trump threatened Tillis with a primary challenge for opposing his massive tax and immigration plan.