New Jersey’s only Democratic House representative who voted against impeaching President Donald Trump is switching political affiliation to the Republican party.

Trump made the announcement with Rep. Jeff Van Drew Thursday at the Oval Office. Van Drew told his staff over the weekend that he would be making the switch.

“I believe that this is just a better fit for me,” Van Drew said of joining the GOP. Trump announced that he is endorsing Van Drew for re-election, calling him “a tremendous asset for the party."

Van Drew’s decision to change parties caused five of his aides to resign. In a letter to Van Drew's chief of staff, the former staffers said, "We greatly respect Congressman Van Drew and are deeply saddened and disappointed by his decision. As such, we can no longer in good conscience continue our service in the Congressman's employ."

The 66-year-old was a conservative state senator before he joined Congress, bucking Democrats on issues including gun control and gay marriage. His district has become increasingly conservative, with Trump carrying it narrowly in 2016 after Barack Obama won it in 2008 and 2012.

Van Drew met last week with Trump, who praised the congressman Tuesday on Twitter.

“Congressman Jeff Van Drew is very popular in our great and very united Republican Party," the president wrote. “It was a tribute to him that he was able to win his heavily Republican district as a Democrat. People like that are not easily replaceable!"

Van Drew says he was pressured by another Democrat not to vote for Impeachment and that prompted him to make the change.