After declining for months to become publicly involved in the race, Hawley endorsed Rep. Vicky Hartzler on Saturday, saying she is the one he believes can win the primary and general election.
His choice raised eyebrows in Trump World, as well as generating hard feelings among other candidates for the Senate nomination. Hartzler has done the least to win the former president's support.
I thought it would be good for me to be involved in this race. The field seemed to be splintering. I think it's important that we hold this seat.
He kept quiet about his choice in the primary.
He said that he gets asked about who he is going to vote for when he is at home.
He said that Hawley was undecided if he would make an endorsement. It was a tough decision to make when he decided it was necessary to weigh in. He didn't make a final decision until Friday, when he would announce the endorsement at the Lincoln Days event.
Reporters were already at the Senate candidate forum when the endorsement came. Should anyone change their mind about running, it would leave 10 days until candidate filing began.
After the Saturday announcement, Hawley said he called Trump, who he has talked to about the Missouri Senate primary often.
Trump has not endorsed in the race.
The polling that showed his endorsement would have a significant impact on the primary was released last month by Hawley's team. 54 percent of GOP voters said his endorsement would make them more likely to vote for a particular candidate, compared to 34 percent who said it wouldn't make a difference.