The battle to pick the Republican nominee for U.S. Senate in Alabama is headed to a March 31 runoff.

Jeff Sessions , President Donald Trump s former attorney general who served as senator until 2017, will face former Auburn University football coach Tommy Tuberville.

Sessions should have been a shoo-in for his old seat. He represented the state in the Senate for 20 years before joining the Trump administration.

He was the first senator to endorse Trump, lending him establishment credibility and opening the doors to the political world during the 2016 election. Trump, in turn, rewarded him with a job as his attorney general.

But Trump soured on Sessions after he refused to act as Trumps personal protector and recused himself from the investigation into Russian interference in the 2016 election. He has called Sessions an embarrassment to the great state of Alabama and said the Justice Department was a disaster when he ran it.