The Supreme Court on Thursday upheld a decision by Ohio election officials who blocked a self-described "progressive" candidate from entering the state Republican primary. 

Samuel Ronan, who was previously a Democratic state and national candidate, had planned to run against Republican incumbent Rep. Mark Carey in Ohio's 15th Congressional District race, according to FoxNews.com. 

Court documents filed in U.S. District Court show that Ronan publicly admitted his candidacy was part of a Democratic strategy to run members of his political party against Republicans in GOP-leaning districts. Ronan's part in the strategy was exposed by a Republican voter, Mark Schare, who shared interviews and social media posts by Ronan revealing he was trying to "trick" GOP voters.