Rep. Kyrsten Sinema (D., Ariz.), the Democratic candidate for U.S. Senate in Arizona, has often discussed her family's military background and endorsements from military veterans on the campaign trail, including the endorsement of a former Army Green Beret who likened Vice President Mike Pence's Christian faith to that of Islamic terrorists.

David Lucier, a member of the Arizona Veterans Hall of Fame Society, said on Sunday that Pence's faith was a "threat to our democracy." He tweeted that "If Pence was a fundamentalist Muslim as opposed to a fundamentalist Christian, he'd be on a most wanted list somewhere in the Special Operations Command."

"A religious fundamentalist is always a threat to our democracy," Lucier added.

If Pence was a fundamentalist Muslim as opposed to a fundamentalist Christian, he'd be on a most wanted list somewhere in the Special Operations Command. A religious fundamentalist is always a threat to our democracy. — David Lucier (@davidflucier) September 9, 2018

Sinema held a "Veterans for Sinema" campaign event Monday alongside Lucier, and she previously touted his support on her Twitter page at least four times since May.

"Proud to have been able to stand with Kyrsten this morning and support her journey to the US Senate," Lucier tweeted following Monday's event.

Proud to have been able to stand with Kyrsten this morning and support her journey to the US Senate. https://t.co/9RXx293wA0 — David Lucier (@davidflucier) September 11, 2018

Sinema has similarly made controversial comments about Republicans. In a 2003 Arizona Republic op-ed, she said "the real Saddam and Osama lovers were Ronald Reagan and George H.W. Bush," referring to the late al Qaeda founder Osama Bin Laden, the mastermind of the Sept. 11, 2001 attacks, and the late Iraqi dictator Saddam Hussein. In the same op-ed, she said there was a "great deal of fun in the anti-war movement" while she was a law student at the Arizona State University College of Law, which has since been named the Sandra Day O'Connor College of Law.

The National Republican Senatorial Committee slammed Sinema for her "silence" on Lucier's tweet, saying it "raises serious questions about her views on people of faith."

"Kyrsten Sinema’s silence raises serious questions about her views on people of faith and whether she agrees that evangelical Christians should be likened to radical Islamic terrorists," NRSC Spokesman Calvin Moore said. "Embracing these kinds of views may score her points with the radical left, but only shows how incredibly out of touch she is with Arizonans."

Sinema faces Rep. Martha McSally (R., Ariz.) this November in the general election. McSally, a retired Air Force officer, was the first woman in U.S. history to fly a fighter jet in combat and the first to command a fighter squadron.