In his first major endorsement of the cycle, Sen. Jim DeMint (R-S.C.) announced Monday that he is backing state Treasurer Josh Mandel for Senate in Ohio.

DeMint’s support is a major indication that various Republican factions are coalescing behind a single GOP candidate to take on Sen. Sherrod Brown (D-Ohio) next year.

“In the Republican primary race, Josh Mandel is the candidate favored by the grassroots,” DeMint wrote on his Senate Conservatives Fund website. “SCF members in Ohio are very excited about his candidacy and have urged us to support his Senate campaign. We’re answering the call today, and we’re going to do everything we can to help the people of Ohio elect a new senator who shares their values.”

The conservative kingmaker’s endorsement comes just a few days after former Secretary of State Ken Blackwell announced he would not run for Senate. Public polls showed Blackwell to be a leading contender in the GOP primary, but Republicans privately expressed concerns about his viability in the general election. Former state Sen. Kevin Coughlin (R) is also running.

In addition to backing Mandel, the Senate Conservatives Fund is also launching a campaign to raise $100,000 for his race before the financial quarter ends Thursday.

Mandel has not announced his candidacy, but he has filed the official paperwork to run and fundraise. He’s expected to make a formal announcement about a bid later this year.

Roll Call Politics rates this race Leans Democratic.