GREENVILLE — South Carolina has a history of nasty politics and that legacy came to life Friday in the Republican race for governor.

Greenville lawmaker Dan Hamilton confirmed a revelation during a news conference when he was endorsing businessman John Warren for governor: An intermediary associated with Gov. Henry McMaster's campaign floated a proposal to pay for a legal challenge filed by Hamilton to delay a June 26 congressional runoff in the vital Upstate.

Pushing back the congressional runoff could send fewer voters to the polls in a region of the state where Warren held an edge on McMaster.

That news set off alarm bells in Palmetto State political circles and vigorous denials from the McMaster camp, who said the claim was unfounded because Hamilton would not name the intermediary.

"This is absolute garbage and a complete and utter lie," McMaster campaign spokeswoman Caroline Anderegg said. "If Dan Hamilton is going to make such a shamelessly false claim, he owes it to the people of the state to prove it or he owes the governor an apology."

She later called the accusation “a hit job.”

Hamilton did not back down from his claim, though he cast doubt later Friday by saying that the conversation was with his campaign team, not himself, and emphasizing that he does not know whether the McMaster campaign directed the offer.

Even with Hamilton’s clarifications, the damage was done.

News about the offer was published statewide and met its intent to cloud a race that will decide the Republican nominee for the state’s top job.

Hamilton’s news also brought Warren, a political newcomer, into the sketchy underworld of South Carolina politics.

The Marine combat veteran had been subject of such attacks, including robocalls that suggested he committed crimes tied to a man with a similar name and a television ad claiming the pro-life candidate supports abortion rights. A pro-McMaster group argued Warren backed Democrat presidential nominee Hillary Clinton because he did not support President Donald Trump during the 2016 GOP primaries.

Warren has taken smaller shots at his rivals. He called Catherine Templeton “conveniently conservative” and criticized McMaster for having ties to targets of the Statehouse corruption probe.

On Friday, Warren was standing next to Hamilton as he revealed word of the shadowy offer that could sway the race.

Hamilton’s claim was taken seriously because of his sterling reputation among S.C. House colleagues, where he served for a decade before running for Congress for the seat held by Trey Gowdy in Greenville and Spartanburg counties.

He finished third in the 12-candidate field, close enough to second to force an automatic recount.

That’s why he said he was offered a chance to file the legal challenge. The thought was he could complain about 15 machines in Greenville — primarily in one precinct — that shut down mid-morning, requiring replacements to be brought in and temporarily causing lines.

Hamilton said he declined.

News about the approach to Hamilton was first reported on, the day before Hamilton and five other top finishers in the 4th Congressional District race were set to endorse Warren. A reporter asked about the allegation at the news conference in Greenville on Friday.

Hamilton did not share many details but still offered a criticism.

"That kind of stuff is the worst in politics and exactly why people are turned off by the political process," Hamilton said.

Warren chimed in, calling the reported offer "shameful."

After Hamilton did little to shed new light on his claims when he clarified some of his comments later Friday, McMaster compared the accusation in a tweet to "lies" leveled at Trump, saying "it was just as appalling then as it is now."

The fight could likely come to a head during a televised debate Wednesday between McMaster and Warren.

The prize at the heart of the dispute is Upstate, South Carolina GOP voter-rich region.

Warren edged McMaster in the 10-county area by 2,000 votes on Tuesday. Warren received 28 percent of the vote statewide.

McMaster won 39 of the state's 46 counties in the five-candidate field and beat Warren handily outside of the Upstate. The former attorney general and lieutenant governor was the top vote-getter in the primary Tuesday with 42 percent.

Warren, though, has been the hottest candidate since entering the race in mid-February. His simple, direct message of being a conservative businessman with Marine combat experience, which was crafted with consultants who worked for Trump's presidential campaign, has lured voters wanting a new face in the Governor's Mansion.

McMaster, 71, has the backing of Trump, a reward for being the first statewide politician in the nation to endorse him during the 2016 campaign when few thought the New York billionaire had a legitimate shot at winning the White House.

The runoff winner will face Democratic state Rep. James Smith of Columbia and American Party candidate Martin Berry in the general election Nov. 6.

Follow Jamie Lovegrove on Twitter @jslovegrove

Jamie Lovegrove is a political reporter covering the South Carolina statehouse and congressional delegation. He previously covered Texas politics in Washington for The Dallas Morning News and in Austin for the Texas Tribune.

Columbia Bureau Chief

Shain runs The Post and Courier's team based in South Carolina's capital city. He was editor of Free Times and has been a reporter and editor for newspapers in Charlotte, Columbia and Myrtle Beach.