Meanwhile, Trump’s running mate, Ohio Sen. JD Vance, is scheduled to appear outside Phoenix Wednesday at a rally with the conservative youth organizing group Turning Point USA, which has been instrumental in remaking the Arizona GOP as a faithful organ of former President Donald Trump’s “Make America great again” movement.

Jimmy McCain’s endorsement and Vance’s Turning Point USA appearance reflect the disparate segments of the GOP that Harris and Trump are trying to reach. Democrats are appealing to traditional conservatives disillusioned by Trump’s takeover of the GOP, while Republicans are looking to shore up their base and ensure that their young supporters turn out.

Jimmy McCain said he had been an independent since leaving the Republican Party after Trump became its standard bearer in 2016. He decided during a nine-month overseas deployment that just ended to switch his registration to Democratic and announce it publicly. His decision was first reported by CNN.

He said he was further “fired up” by the decision after seeing Trump’s campaign visit to Arlington National Cemetery, a visit that Harris called a “political stunt” that “disrespected sacred ground.”

Trump has had a fraught relationship with the McCain family since he denigrated the senator’s status as a war hero during his 2016 campaign.

Jimmy McCain said it was personally difficult for him to hear his father disrespected, but he said his father chose a public life and Americans are allowed to criticize their leaders.

“With Arlington, the people who are buried there gave their lives and the ultimate sacrifice,” McCain said. “They don’t get a political opinion. … We don’t know what those people felt, thought, what they believed. We know they believed in their country and that’s about it.”

Trump said he was invited to Arlington by the families of Marines killed in a suicide bombing during the chaotic U.S. withdrawal from Afghanistan. His campaign released statements from the relatives accusing Harris of playing politics with the issue.

Jimmy McCain, 36, enlisted in the U.S. Marines as a teenager and served four years. He reenlisted in the Army National Guard and was later commissioned as an officer, currently holding the rank of 1st Lieutenant.

Ideologically, McCain said he’s a moderate and harkened back to his father’s 2008 campaign slogan, “Country first.”

“I’m a center man who cares about his country more than anything,” McCain said.

Cindy McCain, the late senator’s widow, endorsed President Joe Biden shortly before the 2020 election, a vote of confidence that helped the Democrat eke out a narrow win in Arizona with support from Republicans disaffected with Trump. Biden appointed McCain to be the U.S. ambassador to the United Nations food and agriculture agencies in Rome, where she is now executive director of the U.N. World Food Programme.

A Navy pilot, John McCain was shot down over North Vietnam in 1967. He was captured, beaten and held prisoner for more than five years, refusing to be released ahead of other American servicemembers.

Trump said of McCain, “He’s not a war hero. He was a war hero because he was captured. I like people who weren’t captured.” McCain later angered Trump with his dramatic thumbs-down vote against repealing Obama’s health care law.

McCain represented Arizona in Congress for 31 years until his death in 2018 from an aggressive brain tumor and built a national reputation as a “maverick” willing to buck his party. While he sometimes took flack from the GOP base and faced fierce primary challengers, he was overwhelmingly reelected and remains a beloved figure in the state.