Early voting in the Arizona primary is underway as the Republican candidates for Senate faced off in a tense debate Wednesday night. 

The debate, hosted by conservative TV network Newsmax, just days before former President Donald Trump is scheduled to campaign in the state, featured venture capitalist Blake Masters, businessman Jim Lamon and retired U.S. Air Force Maj. Gen. Michael McGuire. 

The GOP hopefuls are vying to take on incumbent Democratic Sen. Mark Kelly, who is considered one of the most vulnerable Democrats in the evenly divided Senate, as Republicans look to retake control in the midterm elections. 

With primary day less than three weeks away, recent polls suggest the race could come down to the wire. Ad spending from the top candidates and their supporters is turning the Arizona GOP Senate primary into one of the most expensive primary campaigns of this cycle. 

While the ads have increasingly turned negative, the final primary debate also featured plenty of attacks. Masters and Lamon exchanged sharp words throughout the hour-long debate, as the two look to gain an edge in the closing days. 

A recent poll from OH Predictive Insights showed Trump’s endorsed candidate, Masters, leading Lamon by seven points. But more than a third of voters in the poll also said they remain undecided. 

Lamon said Arizona voters don’t want a “young politician” in Washington, D.C., an apparent swipe at his 35-year-old opponent Masters. 

“Don’t send more young politicians and lawyers, guys, send someone who’s been through the real rigors of American society and work,” Lamon said.  

He also called Masters, who is backed by big tech billionaire and PayPal co-founder Peter Theil, a “California globalist.”

Masters fired back at Lamon saying, “I’ve spent more years of my life in Arizona than Jim Lamon.” 

“You can tell from his accent, he’s from a different part of the country. We welcome people here, that’s fine,” Masters said. “But I am Arizonan, and this is a bulls— attack.”

Masters repeatedly mentioned his endorsement from Trump as he sought to fend off Lamon’s attacks. 

“We need to implement these America first policies,” Masters said. “President Trump trusts me to do that. He met with Jim Lamon, he thought he was a bozo. I am the America first candidate, that is why I am endorsed.” 

While Masters and Lamon spent much of the debate attacking each other, one top-polling candidate was notably missing from the stage. State Attorney General Mark Brnovich was invited, and met the criteria for qualifying, but opted not to attend. 

A spokesperson for Brnovich told CBS News the attorney general was traveling to Washington, D.C. on official business to “fight for the people of Arizona and against the Biden Administration’s open-border policies.” 

This final Republican Senate primary debate, and Trump’s looming visit to the state on Saturday, has put Arizona in the political spotlight. It is one the last major 2022 battleground states to hold a primary this cycle. 

Trump on Saturday will rally for Masters in Prescott Valley, one of the most conservative parts of the state. The former president has inserted himself in several high profile primary battles this year, including in Nevada, Pennsylvania and Georgia. 

The winner of the Aug. 2 primary will take on Sen. Kelly in November. Kelly announced on Wednesday that he’s raised $13.6 million in the second quarter of 2022, and currently has $25 million cash on hand to defend his seat.