Ohio Treasurer Josh Mandel, the presumptive Republican Senate nominee, is now looking over his shoulder at wealthy investment banker Mike Gibbons.

Gibbons, a first-time candidate, entered the May 2018 GOP primary this week with a commitment to raise the millions of dollars he'll need to loosen Mandel's grip on the nomination, even if that means writing a substantial check from his personal fortune. Gibbons, 64, is running as an ideologically flexible political outsider in the mold of President Trump.

"I'm honored to have earned the trust and support of so many who have joined our campaign," Gibbons said Thursday in a statement announcing that he had raised $250,000 in less than 24 hours since he announced for Senate. "It's clear that the people of Ohio are looking for real-world experience, not just another career politician. The response has been overwhelming."

Mandel, 39, is making his second bid for Senate, having lost to incumbent Democratic Sen. Sherrod Brown in 2012. The Mandel campaign is confident in its position, especially after Gibbons garbled his position on abortion on his first day as a candidate, leading to a rebuke from conservative groups in Ohio.

Gibbons initially said that he was not dogmatic on social issues, describing himself as "pro-people." He said that he was personally pro-choice but didn't want to make decision about abortion for women. Gibbons later said that he opposes abortion, supports defunding Planned Parenthood and would vote to confirm Supreme Court justices that would overturn Roe v. Wade.

The Gibbons campaign sees an opening against Mandel, sometimes accused of skirting ethical lines in his aggressive fundraising and use of his political office to promote his Senate campaign. Trump proved that there was a market for an outsider who spoke bluntly against the system and prioritized reform over fidelity to conservatism.

But the Mandel campaign believes that the ingredient Gibbons is missing is Trump's populism — especially against a Democrat like Brown. Trump was a real estate developer and television star who had long spoken out against business and political elites; Gibbons doesn't have that history. The Mandel campaign believes Gibbons career as an investment banker will expose a weakness on international trade, a key issue in Ohio.

Ohio Democrats are just glad that Mandel will now have to contend with a primary opponent. "I don't know much about him but it seems like he's running a professional campaign, which obviously isn't good for Josh Mandel," an Ohio Democratic insider said.

Both Mandel and Gibbons are based in Cleveland.