"We're going to West Virginia tonight, by the way", he said.
Gov. Jim Justice of West Virginia, a Democrat who was elected a year ago even as President Trump carried the state by 42 points, is expected to announce Thursday night at a rally with Mr. Trump that he is changing parties, according to three sources familiar with the plans.
Earlier in the day, Trump said he would be making "a very big announcement" at the rally in the small city along the banks of the Ohio River, whose 49,000 residents have been hard-hit by the opioid crisis and job losses. Before entering politics he gave money to politicians from both parties, and was at times registered as a Republican, Democrat and independent.
Justice's decision is a surprise, considering the Democratic Governor's Association (DGA) spent more than $1 million to get him elected.
Jim Justice is becoming a Republican, but that doesn't mean he'll have the warmest of welcomes in his new political party. Trump campaigned promising to bring back coal mines to states like West Virginia.
The other Democrat in the state, Sen. Manchin is up for for reelection in 2018. That is apparently to come at an event in West Virginia.