EXCLUSIVE Republican Josh Mandel is launching his first major ad blitz in nearly a year in the crowded and combustible race to succeed retiring GOP Sen. Rob Portman of Ohio.

"Josh Mandel. Pro-Gun, Pro-Gun, Pro-Trump," says the narrator in a new ad by the Mandel campaign that was shared first on Tuesday with Fox News.

The ad spotlights the former Ohio treasurer and former two-time Senate candidate’s service in the U.S. Marines.

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"Now is such a challenging time for our nation. A time when the fighter mentality and courage of a United States Marine are vitally needed in the U.S. Senate," the narrator says. "Josh Mandel is that Marine. Served two tours in Anbar Province."

And the commercial includes a soundbite from Ben Adkins, who's described as Mandel's drill instructor, saying "I know he’s prepared. He’s been tested. And he’s passed."

The spot concludes with Mandel saying "you want a fighter? Send in the Marine."

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Mandel's campaign tells Fox News the commercial, which starts running on Wednesday, is the first in a large $2 million statewide ad blitz on broadcast and cable TV, and digital.

Mandel is one of the top contenders in a large field of Republican Senate candidates vying for their party's nomination.

Josh Mandel campaigns

Republican Senate candidate and former Ohio treasurer Josh Mandel speaks to the Geagua County Conservative Club in Chesterland, Ohio, on May 20, 2021. (Josh Mandel Senate campaign)

Among his major rivals are Mike Gibbons, a Cleveland entrepreneur, real estate developer and investment banker who’s making his second bid for the Senate GOP nomination, former Ohio GOP chair Jane Timken, J.D. Vance, a hedge fund executive and the author of the best-selling memoir "Hillbilly Elegy."

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All four candidates for months have been making a full court press to earn the endorsement of former President Donald Trump, who remains very popular and influential with Republican voters in Ohio and across the country as he continues to play a kingmaker’s role in GOP primaries and repeatedly teases another White House run in 2024. 

The only candidate among the leading GOP contenders in the race to succeed retiring GOP Sen. Rob Portman not to make a full-court press to land Trump’s endorsement is state Sen. Matt Dolan, a former prosecutor whose family owns Major League Baseball’s Cleveland Guardians, formerly known as the Indians.

With GOP primary field chock-full of wealthy contenders who are also backed by well-financed super PACs, nearly $20 million has been spent to date to run ads, according to figures from the national ad tracking firm AdImpact

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Club for Growth Action, which is supporting Josh Mandel, has dished out more than $3 million to run ads.

Nearly all the ad spending, with just over two months still to go until Ohio's scheduled May 3 primary, has been on the Republican side.