Texas Representative Chip Roy is reportedly challenging New York Rep. Elise Stefanik to fill the House GOP Conference Chair position left by Liz Cheney. Roy has an uphill battle ahead as Rep. Stefanik has already received endorsements from top House Republicans Kevin McCarthy and Steve Scalise along with former President Trump.

The Hill reports:

Roy, a member of the far-right Freedom Caucus, made waves earlier this week when he sent a memo to colleagues raising concerns that Stefanik was too liberal to represent the 212-member conference and that GOP leaders were rushing to “coronate” her.

Stefanik previously was a leader of a group of moderate Republicans before becoming one of Trump’s most vocal defenders on Capitol Hill.

Roy specifically pointed to Stefanik’s past votes against the 2017 tax cut law and in support of Democratic bills to end Trump’s emergency declaration to fund a border wall, keep the U.S. in the Paris climate pact and ban discrimination based on sexual orientation and gender identity.

“We must avoid putting in charge Republicans who campaign as Republicans but then vote for and advance the Democrats’ agenda once sworn in – that is, that we do not make the same mistakes we did in 2017,” Roy wrote in the memo.

After announcing the challenge former President Trump sent out a message emphasizing his support for Re. Stefanik over Roy.

“Can’t imagine Republican House Members would go with Chip Roy—he has not done a great job, and will probably be successfully primaried in his own district. I support Elise, by far, over Chip!” Trump said.