Vice President Kamala Harris is appealing directly to Arizona Republicans wary of former President Donald Trump, hoping a dose of crossover support will allow her to clinch the swing state.

The 30-second ad, titled “Cities,” features Mesa Mayor John Giles, an outspoken critic of Mr. Trump who backed Ms. Harris earlier this year.

“I’m a lifelong Republican, but I’ve always put country over party and I know Donald Trump’s second term would be all about himself,” Mr. Giles says in the ad. “That’s why like so many other Republicans, I cannot support Donald Trump. Kamala Harris and I may not agree on everything, but I do know that she will always put country first.”

---

---

Arizona is a vital swing state that will award 11 electoral votes in November.

Ms. Harris and President Biden won it en route to victory in 2020, but the state is a toss-up this time, with many polls showing a slight lead for Mr. Trump.

Both candidates and surrogates such as first lady Jill Biden have visited the state in recent days.

At a rally Sunday in Prescott, Mr. Trump vowed to “rescue” the state from Ms. Harris’ “reign of terror.”

“We are going to usher in a new Golden Age of American success for the citizens of every race, religion, color, and creed,” Mr. Trump said. “What Kamala and her radical left cronies have done to the state of Arizona is a crime that can never be forgiven.”

Ms. Harris’ use of Mr. Giles fits a pattern of enlisting lifelong Republicans who don’t trust Mr. Trump, including former Sen. Jeff Flake of Arizona, former Rep. Liz Cheney of Wyoming and her father, former Vice President Dick Cheney.

Ms. Harris’ GOP supporters often cite Mr. Trump’s temperament as the reason they are crossing party lines.

“If we’re gonna make progress as a country, we have to have an adult in the White House,” Mr. Giles says in the new ad. “That’s why I’m supporting Kamala Harris.

• Seth McLaughlin contributed to this story.