COLUMBUS, Ohio (AP) — Ohio’s moderate Republican senator, Rob Portman, has thrown his support behind Ohio Treasurer Josh Mandel for U.S. Senate.

In a video posted early Wednesday morning, Portman urged Republicans in the battleground state to unify behind Mandel as he makes a second consecutive run to unseat Democratic incumbent Sherrod Brown.

Portman said Mandel, 39, is a Marine veteran and a fiscal conservative who he could work with “to get this economy moving again, to fight for more jobs and higher wages, and to restore America’s leadership role in the world.”

Portman’s backing came about a week after Republican U.S. Rep. Pat Tiberi, a potential formidable rival to Mandel, announced he wouldn’t seek the Senate seat.

The senator’s early support could deter other GOP challengers — including Republican state officeholders lining up in a crowded governor’s race — and allow Mandel to target all of his resources to fighting Brown. His supporters already have launched a super PAC to support him that can raise and spend unlimited amounts from undisclosed donors, signaling another expensive and negative contest likely is ahead.

Brown, 64, is a veteran politician repeatedly elected by Ohio voters. He’s among a group of Democrats considered vulnerable in 2018 because their states went strongly for Republican President Donald Trump last year.

Portman’s endorsement could help Mandel among Ohio’s traditional Republicans and independents, as he positions himself further to the right than when he ran against Brown last time.

He has described his 2018 campaign as Trump-esque. It’s a move that has caused no love loss with Republican Gov. John Kasich, a leading Trump detractor nationally. Kasich has signaled he may not endorse Mandel if he turns out to be a “negative guy.”