The Republican from North Carolina announced he won’t run for reelection next year amid sharp disagreements with President Trump.

Thom Tillis' surprise retirement announcement over the weekend creates a sudden opening in next year’s midterm elections, setting off a scramble of successor speculation that includes both a former Democratic governor and a Trump other than the one who ultimately nudged Tillis into leaving.

Republican North Carolina Sen. Thom Tillis will not seek reelection, according to a statement released by his office Sunday afternoon.