Ahead of Donald Trump’s visit to the state this weekend, the two leading candidates in the GOP Senate primary in Arizona duked it out in an explosive final debate Wednesday, fighting over who the real “America First” candidate is. Former energy executive Jim Lamon called Blake Masters “a fake” border hawk and accused him of using “California talk, buddy, not Arizona [talk].” But at the end of the day, it’s Masters, not Lamon, who has the former president’s backing and will be promoted at the “Arizona Trump Ticket” rally on Saturday.

Masters, a Silicon Valley egghead plucked out of obscurity by PayPal cofounder Peter Thiel, touted his recently obtained MAGA credentials at length Wednesday. “President Trump endorsed me because he knows that I’ll be the best on the border,” he said. “I’m the only one bold enough to say that I think Joe Biden and [Secretary of Homeland Security Alejandro] Mayorkas deserve to be impeached for the dereliction of duty that they’ve shown at the southern border.” After vowing to never give “Biden a damn thing” if elected, Masters taunted Lamon for failing to charm Trump during his unsuccessful visit to Mar-a-Lago, saying, “He met with Jim Lamon, he thought he was a bozo. I’m the ‘America First’ candidate. That’s why I’m endorsed.” Lamon noted that Masters’s campaign and career has been bankrolled by a Big Tech billionaire. “Look no farther than who’s holding the purse for this guy,” Lamon said of Masters, repeating material from attack ads against the Thiel protégé. “$17 million dollars coming out of Big Tech California globalist guy who he will owe that too.”

Trump is visiting Arizona, a state he lost to Joe Biden in the 2020 election, Saturday, with a rally scheduled in a conservative county north of Phoenix, where he’s expected to speak in support of Masters and Kari Lake, the Republican running for governor. The campaigning trip also comes amid reports of Trump’s intentions to run for office again in 2024 (Trump himself told New York magazine as much in a recent interview). Still, his visit will put a spotlight on the Senate contest in Arizona, where Republicans are attempting to oust Democrat Mark Kelly from office.

There was one notable absence from the Republican primary debate: Mark Brnovich, Arizona’s ardently conservative attorney general, was busy fighting “against the Biden administration’s open-border policies,” his office told CBS News. His lack of participation likely came as a disappointment to some conservatives, who saw Brnovich as the GOP’s best chance to defeat Kelly in the general election. After leading polls for months, Brnovich began to steadily bleed support this spring, particularly after Trump endorsed Masters in early June. Trump has also repeatedly disparaged Brnovich, calling him a “disappointment” for not using his power as Arizona’s top prosecutor to overturn Biden’s 2020 victory in the state.

The debate, which was hosted on Newsmax, did feature former Arizona National Guard leader Mick McGuire, a relative non-factor in the race, as a third participant. Though, McGuire did make his presence known by attacking both Masters and Lamon at the same time. “I’m not sure if self-funding from a California billionaire or yourself is better, but the truth of the matter is we’ve never had a self-funder elected statewide in this state in over 100 years,” McGuire said.