Republican Kentucky Rep. Thomas Massie announced Monday that he is backing Kelli Ward in her primary challenge against Republican Arizona Sen. John McCain.

“We need Dr. Ward in the U.S. Senate to stand with Rand Paul and Mike Lee. Her insights from the real world as a mother, military wife, and physician will be an invaluable addition in the fight against career politicians to reduce spending, reverse our national debt, repeal Obamacare, and return to a responsible foreign policy,” Massie, who is a member of the House Liberty Caucus, said in a statement.

“The founding fathers sought to limit the federal government and preserve the power of the states in the Tenth Amendment to the Constitution. Dr. Kelli Ward is one of the few who really gets it,” Massie continued on to say.

McCain’s primary is on August 30 and the most recent poll shows him leading Ward with a 21 point lead. This is a much slimmer lead than House Speaker Paul Ryan had against his insurgent primary opponent Paul Nehlen.

Ward, like Nehlen, is a strong supporter of Donald Trump. Ward recently said, “John McCain can hardly bring himself to utter the name ‘Donald Trump,’ much less explain why he supports ‘the nominee.'”

Despite McCain’s lukewarm support for Trump, the GOP nominee has endorsed the Arizona senator.