Trump and McMaster (copy) (copy)

Gov. Henry McMaster and President Donald Trump at a rally in South Carolina during the 2016 presidential campaign.  File/AP Photo/John Bazemore

COLUMBIA — President Donald Trump and Vice President Mike Pence are coming to South Carolina to campaign for Gov. Henry McMaster in the final days before his closer-than-expected GOP primary runoff against Greenville businessman John Warren.

Trump will visit Monday, the day before McMaster's showdown with Warren, a political newcomer using the president's rhetoric, and who has gained popularity since joining the race just four months ago.

Trump, making his second campaign trip for the governor, will visit Columbia, a source close to the McMaster campaign said Tuesday.

Pence is coming Saturday for his first visit to stump for McMaster. He is heading to Myrtle Beach, the source said.

"This is a big thing. It's unprecedented," Greenville political consultant Chip Felkel said. "They realize Warren is surging and they're not going to leave anything on the table."

The visits are McMaster's reward for being the first statewide elected official in the nation to back Trump's 2016 presidential run despite being the kind of career politician that Trump and his supporters rail against. McMaster first ran for office in 1986, and he has been a state party chairman, attorney general and lieutenant governor before being promoted to governor last year with Nikki Haley's departure to the United Nations.

"Seems to be about loyalty for (Trump)," College of Charleston political scientist Gibbs Knotts said. "It's strange to have a president come down for a primary like this. But with Donald Trump, it's been a strange couple of years."

Trump has been vital to McMaster as he tries to win his first full term as governor. The president holds an 80 percent approval rating among South Carolina Republicans, according to a Winthrop University poll in April.

Snippets of Trump's 25-minute speech at a Greenville fundraiser in October have dominated McMaster's campaign television ads. The governor, who often mentions his White House ties in stump speeches, took a call from Trump during a news conference in North Charleston on Monday. He said they spoke about the greatness of South Carolina and the nation.

"President Trump and Vice President Pence are changing the world, and we couldn’t be more excited to have their support," McMaster said in a statement. "That they are both willing to come and campaign to keep South Carolina moving forward is a testament to the success of our great state, to the things we’ve accomplished over the last few years, and to the strength of our people."  

Trump's campaign visits have not always translated into wins at the ballot box. The president stumped for Luther Strange in the Alabama Republican Senate primary runoff last year against Roy Moore, who ended up winning the nomination.

But Strange was the underdog in that race. McMaster, the top vote-getter in the five-candidate primary field on June 12, is the favorite.

Having the president and vice president visit South Carolina in the final days before the runoff could blunt Warren's momentum that shot him into second place in the primary.

Warren rode a carefully sculpted brand as a conservative businessman, political outsider and Marine combat veteran that was crafted by consultants and pollsters who worked on Trump's 2016 campaign.

He led in the state's GOP-voter rich Upstate region during the primary but McMaster dominated voting in the rest of the state to secure a 14 percentage-point advantage.

Warren has closed that gap and received endorsements from the race's third- and fourth-place finishers, Lt. Gov. Kevin Bryant and former two-time state agency head Catherine Templeton. Templeton was considered by the Trump administration for labor secretary. Warren has announced that Phil Robertson, star of the reality TV show "Duck Dynasty," will campaign for him in Greenville on Thursday. 

Warren uses the president's familiar language about dramatically changing government and brags about being the more Trump-like candidate because he is new to politics and runs a specialty real estate lending firm. 

"This campaign is about who has the best vision to clean up corruption in Columbia and hold state government accountable to the taxpayer," Warren said in a statement. "As the conservative outsider in this race, I am committed to shaking things up and draining the swamp in Columbia like President Trump is doing in Washington."

The president is flying to South Carolina for just that reason, Knotts said, so voters know who he backs in a race where light turnout is expected.

"He wants to make sure there are no imposters," Knotts said.

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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.