In a tight and fiercely competitive race, former state Sen. Mike Mazzei emerged as the Republican nominee for Oklahoma's governor, narrowly defeating Oklahoma Attorney General Gentner Drummond. The primary victory on Tuesday was significantly bolstered by former President Donald Trump's endorsement, a substantial personal financial injection into his campaign, and considerable support from external funding sources.

The primary win marks a crucial rebound for Trump, whose recommended candidates have recently faced a series of defeats in similar gubernatorial primaries across states such as Wyoming, Iowa, Georgia, Minnesota, and South Carolina. This victory in Oklahoma provides a much-needed boost to Trump's influence within the party, especially following the loss of Trump-endorsed candidates in House races in Michigan and Florida earlier in the month.

Trump threw his support behind Mazzei in May, just before the state’s open primary. Despite Trump's endorsement, the primary race remained tightly contested. Drummond initially led Mazzei by a marginal 0.3 percentage points in the first round on June 16, which led to Tuesday's runoff. This election cycle was marked by unprecedented campaign spending, making it one of the most expensive primaries in Oklahoma's history.

Mazzei's campaign was notable for its financial scale; he loaned his campaign a whopping $11.6 million, dwarfing Drummond's self-funded $3 million. Additional financial firepower came from the conservative Club For Growth, which spent approximately $8 million on television advertisements supporting Mazzei and criticizing Drummond, as reported by AdImpact.

Further bolstering Mazzei's campaign were endorsements from notable state figures including Governor Kevin Stitt and former Congressman and current Homeland Security Secretary Markwayne Mullin. These endorsements, combined with Trump's backing and substantial campaign funding, provided Mazzei with a significant edge over Drummond.

Before his run for governor, Mazzei served 12 years in the state senate, until he was term-limited out in 2016. He briefly joined Governor Stitt’s administration in 2019 as a budget secretary. With a strong Republican backing and a significant lead in resources and endorsements, Mazzei is now poised as the overwhelming favorite against Democratic challenger, State Rep. Cyndi Munson, in the upcoming general election—a contest in a state that Trump won by 34 points in the 2024 Presidential Election.