It’s one of the most crowded and competitive Republican Senate primaries in the 2022 election cycle, and as all but one of the major candidates in Ohio's GOP showdown spotlight their support for Donald Trump in hopes of earning the former president’s endorsement, the race has turned increasingly combustible.

Helping to fuel the fireworks – a GOP field chock-full of wealthy contenders who are also backed by well-financed super PACs. It’s resulted in more than $16 million being dished out to date on the ad wars, with two and a half months still to go until Ohio's May 3 primary.

THE $20M AND $16M SLUGFESTS: AD SPENDING SOARS IN PENNSYLVANIA AND OHIO SENATE RACES

The latest shot in the firefight among the leading contenders came this week, as a new ad by Republican candidate Mike Gibbons attacked rivals J.D. Vance and Jane Timken.

MIke Gibbons

Mike Gibbons, a Republican Senate candidate in Ohio, speaks to supporters during a campaign rally in Maineville, Ohio, Jan. 14, 2022.  (AP Photo/Jeff Dean)

"J.D. Vance called Donald Trump an idiot," says the announcer in the spot, which is running statewide in Ohio.

This isn’t the first time Gibbons, a Cleveland entrepreneur, real estate developer and investment banker who’s making his second bid for the Senate GOP nomination, has targeted Vance, a hedge fund executive and the best-selling author of the memoir "Hillbilly Elegy." A Gibbons ad in December charged that Vance was "cheering for the wrong team." 

TRUMP HELPS CLEAR THE FIELD IN OHIO'S CROWDED SENATE GOP PRIMARY

And Vance has also taken incoming fire from commercials by two outside groups backing another leading contender – former Ohio treasurer and former two-time Senate candidate Josh Mandel.

Vance, whose political team includes some veterans of the Trump White House and presidential campaigns and who has showcased his support for the former president and his polices, came under attack after entering the race last summer for his past criticisms of Trump during the 2016 presidential campaign.

J.D. Vance jumps in to the Ohio Senate GOP primary

Republican Senate candidate J.D. Vance launches his 2022 campaign at an event in Middletown, Ohio, on July 1, 2021. (J.D. Vance)

The Marine veteran and social media pundit, who’s running a populist campaign, has explained that "I think like a lot of conservatives in 2016, I’d been let down too many times. I didn’t think that any politician would deliver on their promises and President Trump proved me wrong." And he’s noted that what "changed my mind about Donald Trump more than anything is that I saw the corruption in our institutions."

A pro-Vance super PAC went up last week with a large seven-figure ad blitz spotlighting the candidate’s conservative and populist credentials. The commercial then uses a clip of Vance arguing that "the elites plunder this country and then blame us for it in the process." 

THE MASSIVE AD BLITZ TO REINTRODUCE VANCE TO OHIO VOTERS

The "Protect Ohio Values" super PAC is financed by a massive $10 million contribution from Vance’s old boss, billionaire venture capitalist, PayPal co-founder and Trump ally Peter Thiel

Gibbons' ad also targets Timken, who last year stepped down as Ohio GOP chair to launch her Senate campaign.

"Jane Timken defended a RINO congressman after he impeached Trump," the announcer in the spot emphasizes. And the announcer showcases that "Mike Gibbons is Trump tough."

Jane Timken

Ohio Senate candidate and former state GOP chair Jane Timken signs a "Stop Critical Race Theory" pledge, at her campaign office in Columbus, Ohio, on July 12, 2021.

The commercial refers to Timken’s initial support for Rep. Anthony Gonzalez of Ohio, who was one of the 10 House Republicans who voted 13 months ago to impeach Trump for inciting the deadly Jan. 6, 2021, attack on the U.S. Capitol by right-wing extremists aiming to disrupt congressional certification of Joe Biden's 2020 election victory.

FORMER TOP TRUMP ADVISER KELLYANNE CONWAY ENDORSES TIMKEN

Timken, at the time, described Gonzalez as "an effective legislator, and he's a very good person," but weeks later she described his impeachment vote as a "wrongful decision" and urged him to resign.

The Gibbons campaign told Fox News that "we’re trying to make sure Ohio voters know what these candidates have said and what their real record is."

Timken, like Gibbons, Vance and Mandel, has also touted her support for the former president, with an ad in December titled "America First" describing her as a "Trump conservative."

Josh Mandel campaigns

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

The only candidate among the leading 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.

The sniping among the candidates dates back to February of last year, when Mandel and Timken – the first two major contenders to enter the race – started trying to outdo one another in spotlighting their Trump credentials.

TRUMP 2020 CAMPAIGN MANAGER BILL STEPIEN JOINS GIBBONS CAMPAIGN

A month later, Trump quizzed Mandel, Timken, Gibbons and Cleveland-based businessman and luxury auto dealership giant Bernie Moreno (who suspended his campaign earlier this month) about their support in a private meeting with the four candidates ahead of a fundraiser at his golf course in Palm Beach, Florida.

Fast-forward to today and the campaigns are continuing to tout their Trump connections. Gibbons last week highlighted that Trump 2020 presidential campaign manager Bill Stepien was joining his team as a top adviser. This week Timken spotlighted the endorsement of Trump 2016 general election campaign manager and White House senior adviser Kellyanne Conway, who previously had backed Moreno. 

Matt Dolan campaigns

Ohio state Sen. Matt Dolan, who's running for the GOP U.S. Senate nomination in Ohio, campaigns in Independence, Ohio, on Dec. 1, 2021. (Matt Dolan campaign )

The Ohio Senate race has become the second most expensive in the country this cycle, behind the showdown in the neighboring battleground state of Pennsylvania for another GOP-held open seat. In both states, nearly all the ad spending is on the Republican side.

The Ohio Democratic Party has been feasting on the GOP discord, and late last year started a weekly newsletter titled "Buckeye Brawl" to highlight "just how nasty, chaotic and expensive this Republican Senate primary has become."

The Democratic Senate primary – in comparison to the GOP slugfest – has been a sedate affair. 

CLICK HERE TO GET THE FOX NEWS APP

Longtime Democratic Rep. Tim Ryan of northeastern Ohio is the front-runner in a very small field of contenders that also includes progressive Morgan Harper, a former Consumer Financial Protection Bureau senior adviser and 2020 congressional candidate.

But the eventual Democratic nominee will likely face somewhat of an uphill climb in Ohio’s general election. The Buckeye State was once a premiere battleground in presidential contests and was the deciding state in then President George W. Bush’s razor-thin 2004 re-election. But Trump won the state by eight points in his 2016 election to the White House and by the same comfortable margin in his 2020 re-election defeat.