Sen. John Cornyn is the second incumbent to lose a primary this cycle after Trump made a late endorsement of Texas Attorney General Ken Paxton.

Paxton faces Democrat James Talarico in the general election.

President Donald Trump abandoning Sen. John Cornyn destabilizes the White House's already-rocky relationship with Senate Republicans.

Cornyn led the March primary with 42% of the vote, narrowly ahead of Paxton’s 40.5%, sending both to a runoff.