WASHINGTON (Reuters) - President Donald Trump announced on Thursday that a Democratic U.S. lawmaker who opposed his party’s move to impeach the Republican president was switching parties, a day after the House of Representatives approved articles of impeachment.

Jeff Van Drew, who represents a district in southern New Jersey, was at Trump’s side when he made the announcement during a White House appearance.

“Very big announcement ... Jeff will be joining the Republican Party,” Trump told reporters during an Oval Office event to highlight Van Drew’s switch.

Van Drew said he believed in what Trump was doing with the economy and he had come to the conclusion that the Republican Party was a better fit for him.

“You have my undying support,” he told Trump, who returned the compliment by saying he would endorse Van Drew in his 2020 congressional bid.

Van Drew, 66, was one of only two Democrats who voted on Wednesday against both articles of impeachment, which accuse Trump of abuse of power and obstruction of Congress.

Republicans had warned that lawmakers like Van Drew who represent districts that backed Trump in the 2016 presidential election would face a backlash if they supported impeachment. However, all but three of the 31 lawmakers from Trump-won districts voted for both articles of impeachment.

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Van Drew had said he did not think Democrats had made their case that Trump improperly pressured Ukraine to investigate a political rival. He told reporters after the vote that it would boost Trump’s prospects in the 2020 presidential election.

A dentist and dapper dresser whose district includes the casino town of Atlantic City, Van Drew, 66, was the first Democrat to represent the area in nearly a quarter-century when he was elected last year.

His defection does not threaten Democrats’ control of the House, where they hold a 232-198 majority.

Some of his congressional staff quit this week after reports that he would change parties. The Blue Dogs, a group of moderate Democrats in the House, suspended him from the group on Tuesday.

Republicans said his defection illustrated the weakness of the Democrats’ case against the president.

“How can you be excited if you started this whole process thinking the outcome would be better, and your own conference got smaller because of it?” said House Republican Leader Kevin McCarthy.