Jimmy McCain, a son of the late Arizona senator, registers as a Democrat and backs Harris

PHOENIX — Jimmy McCain, a son of former Arizona senator and 2008 Republican presidential nominee John McCain, said this week he has registered as a Democrat and will vote for Vice President Kamala Harris, a valuable nod of support for the Democratic nominee in a battleground state.

Meanwhile, Trump's running mate, Ohio Sen. JD Vance, appeared outside Phoenix Wednesday for an event 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.

Democrats have made big inroads over the last six years in Arizona, once a Republican stronghold that routinely backed McCain and other Republicans for president, with an anti-Trump coalition that includes Republicans and conservative independents.

That reality is clear in each campaign's approach to winning the state. Harris has staked out moderate positions in contrast to the progressive stances she outlined in her 2020 Democratic primary campaign, including on the border, an important issue in this border state, while elevating Republican backers.

Trump, meanwhile, is counting on support from young voters turned off by politics and distrustful of institutions. He chose Phoenix for a rally joining forces with Robert F. Kennedy Jr., who abandoned his own independent campaign to back Trump.

The Turning Point event where Vance spoke was aimed at promoting the group's ''chase the vote'' initiative to identify supporters who might need an extra nudge and ensure they participate. The event, at a mega church on the outskirts of metro Phoenix, began with a concert by a Christian rock band with a heavy, seat-shaking base and a colorful light show.

''We just want Americans to be able to live a decent life in the country their parents and grandparents built,'' Vance said.

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.

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.

''There has been no greater advocate for our brave military men and women than President Trump,'' said Karoline Leavitt, Trump's national press secretary. He secured new military investments and pay raises for troops while he was in the White House, and no new wars broke out, she said.

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 hearkened 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.

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.

Still, the endorsement won't sway the Republicans who still dislike McCain.

''I didn't respect John McCain,'' said Jerry Lyn of suburban Phoenix, who went to the Turning Point rally because he's been so impressed by Vance he wanted to see him in person. ''I really didn't. He did a lot of bad things and people don't realize it.