COLUMBUS — A disqualified candidate for Ohio governor has lost his court case seeking to get back on the ballot.

In a 6-0 ruling Thursday, the Ohio Supreme Court said Democrat Jon Heavey failed to prove enough of his signatures had been improperly thrown out.

The decision leaves four candidates to fight out the Democratic gubernatorial primary: former consumer watchdog Richard Cordray, former U.S. Rep. Dennis Kucinich, state Sen. Joe Schiavoni and former Ohio Supreme Court Justice William O’Neill.

Heavey was a last-minute entrant into the race to succeed Republican Gov. John Kasich, who’s term-limited. He is a Cleveland doctor and venture capitalist who sunk $1.5 million of his own money into his campaign.

Justice Pat DeWine, son of gubernatorial candidate Mike DeWine, recused himself from the case.