Justice, a coal magnate and the wealthiest man in West Virginia, first won office last year. Before announcing his candidacy, he was wooed by both Democrats and Republicans. Ultimately, he opted to run as a Democrat.

Justice’s party switch is a slap in the face to the Democratic Governors Association, which spent more than $1 million to try to get Justice elected in 2016. The Republican Governors Association spent $3.7 million backing his GOP rival.

Trump took 68 percent of the vote in West Virginia in 2016, beating Hillary  by 41 points. Justice, who faced the Republican state Senate president in November, won office with 49 percent of the vote.

Justice, the only billionaire in West Virginia, is the chief executive officer of dozens of companies, many in the coal industry. He also owns the Greenbrier, a luxury resort in the Allegheny Mountains that once served as a bunker meant to help the U.S. government survive a nuclear attack.

The New York Times first reported Justice’s decision to flip parties.

Trump seemed to tease the announcement earlier Thursday during an event spotlighting telehealth efforts by the Department of Veterans Affairs.

“We’re going to have a very big announcement, which will be very exciting I think for the media and everyone else,” Trump said. “I believe I’ll be making it in West Virginia, so that will be very exciting.”

Trump will fly to Huntington, W.Va., late Thursday for a rally at the Big Sandy Superstore Arena. It is his second visit to West Virginia in a little more than a week, following a speech to a Boy Scouts Jamboree.

That event took place at the James C. Justice National Scout Camp, a facility named for the governor.