(CNN) Former President Donald Trump has endorsed Arizona Senate hopeful Blake Masters in a move that aides believe will give the Republican significant momentum ahead of the state's August primary.
Calling Masters "a great modern-day thinker," Trump praised the tech entrepreneur Thursday in a statement that underscored the candidate's commitment to the former President's top priorities -- from immigration and gun rights to relitigating the 2020 election.
"Blake knows that the "Crime of the Century" took place, he will expose it and also, never let it happen again," Trump said in a statement, referring to false claims of electoral fraud in 2020.
Masters, who is also backed by conservative tech billionaire Peter Thiel, is running in a crowded field of GOP candidates seeking to take on Democratic Sen. Mark Kelly in November.
Trump took his time making the endorsement, surveying aides over the past several months -- including some who are working for rival candidates Mark Brnovich, the state attorney general, and solar energy entrepreneur Jim Lamon. But advisers to the former President have previously told CNN the outcome of the Ohio Senate primary in early May was good news for Masters, who, like Ohio GOP Senate nominee J.D. Vance, is a prominent Thiel acolyte.
Thiel had privately lobbied Trump to endorse Vance and Masters, in addition to pouring millions into super PACs supporting both men. Just weeks before Trump unveiled his endorsement of Masters, Thiel made another $3.5 million contribution to Saving Arizona, the Masters-aligned group -- on top of an initial $10 million investment.
"President Trump is a great man and a visionary," Masters said in a statement released by his campaign. "It's incredible to have his endorsement. I wish everyone could know how this feels."
"Soon we will have a young, fearless, dynamic America First coalition in the U.S. Senate and that is thanks to Donald Trump," Masters said.
Lamon said that he was "especially disappointed" in Trump's endorsement of Masters and that his rival "would be shred to pieces" by Kelly in a general election. A statement Thursday from Brnovich campaign manager Brandon Urness did not mention the latest development but noted that Brnovich "intends to fight and win this Primary Election and we look forward to working with President Trump to defeat Mark Kelly this fall."
Trump's decision to endorse Masters aligns him, in this race at least, with the Club for Growth, which has been at odds with the former President in other contests. In the Ohio GOP Senate primary, for example, the club backed former state treasurer Josh Mandel and refused to end its negative ad campaign against Vance even after he earned the former President's endorsement.
"When Club for Growth Action and President Trump work together, real conservatives win, and that's exactly what will happen in Arizona," David McIntosh, president of Club for Growth Action, said in a statement Thursday welcoming Trump's endorsement of Masters.
But the campaign arm of Senate Democrats said Trump's move would exacerbate divisions in the GOP primary.
"Now his endorsement will only intensify this intra-party fight, just like it has in GOP Senate primaries across the country -- leaving whichever candidate limps out of their primary badly damaged and on the wrong side of the voters who will decide the general election," Patrick Burgwinkle, a spokersperson for the Democratic Senatorial Campaign Committee, said in a statement.
Kelly, who won a special election in 2020 for the remaining two years of the late GOP Sen. John McCain's term, is unopposed in the Democratic primary as he seeks a full six-year term.
The Arizona primary elections are scheduled for August 2.
This story has been updated with additional reaction and background.