Former President Trump is offering to back a primary challenger to Rep. John Katko (R-N.Y.) after Katko voted to impeach Trump.

Trump sent the letter to the chairman of the Onondaga County Conservative Party detailing his support for a primary challenge, Syracuse.com reported. Bernie Ment, the party’s chairman, said he got the message on Monday.

The outlet obtained the letter, written on top of an April 23 article by Syracuse.com with the headline “Onondaga County Conservative Party dumps John Katko over Trump impeachment vote.”

“A great move,” Trump wrote overtop the article. “Katko will never win again. He is bad news. Please thank all including those in Wayne and Cayuga — and now Onondaga.”

“I won big in area. Will help with campaign — find a great candidate,” Trump wrote.

In addition to voting to impeach Trump, Katko also negotiated with his Democratic counterpart on the House Homeland Security Committee on an agreement for an independent commission to investigation the Jan. 6 attack on the U.S. Capitol. That agreement was ultimately rejected by most Republicans.

Katko is the only one out of the 10 House Republicans who voted for Trump’s impeachment that has yet to receive a primary challenger. 

Trump has vowed to help oust any Republican he deems insufficiently loyal in 2022, especially the 10 who voted to impeach him. Many of those have gotten challengers who are major supporters of the former president. A number have also faced backlash in their home districts. Four county Republican parties in Katko's district have said they will not endorse him in his next primary.

President Biden beat Trump by 9 points in Katko's district in the 2020 presidential election.

Ment told Syracuse.com the party is waiting until redistricting is done in New York before picking a candidate to run against Katko.

“It was a surprise to me this morning when I got [the letter],” Ment said. “I was shocked. It just turned up out of the blue.”