COLUMBIA, S.C. -- South Carolina voters head back to the polls on Tuesday for a runoff that will decide the Republican nominee for governor in a fierce contest between two prominent state figures.

President Donald Trump first backed Lt. Gov. Pamela Evette against state Attorney General Alan Wilson, and neither secured enough votes in the June 9 primary to avoid the runoff. Yet as Wilson gained traction, Trump shifted on Friday to endorse both candidates, leaving voters without clear direction from the president.

Trump's backing has swayed many primaries this cycle, though his picks in Iowa and Georgia did not prevail in recent governor contests.

For months, the race has featured heavy television ads, mailers and billboards as candidates sought attention in South Carolina's first open governor's race in over a decade. With Trump still popular locally, ties to the president became central for all Republican hopefuls despite some national concerns over issues like the economy.

Just days before the runoff, the two met in their sole debate.

Because each received rebuttal time after any mention of their name, the opening segment quickly turned into rapid exchanges over claims of negative campaigning and pay raises funded by taxpayers, with the crowd responding through loud jeers and cheers.

Observers at the Coastal Carolina University venue saw attendees depart amid the ongoing noise, which at times overpowered the candidates and drew no response from moderators.

Wilson criticized Evette for missing earlier debates and for misstating her role in signing bills actually handled by Gov. Henry McMaster. Evette countered by labeling Wilson a career politician and noting Trump's initial primary support for her.

Throughout the campaign, Evette has stressed Trump's choice of her as his preferred candidate and has received McMaster's endorsement from their prior races together.

Right after Trump's dual endorsement, Wilson also highlighted the support. Shortly after Trump's social media post, Sen. Tim Scott announced his Wilson backing, and sources indicated Scott made calls and raised funds while urging Trump to include Wilson.

Wilson gained endorsements from earlier primary dropouts such as U.S. Reps. Ralph Norman and Nancy Mace plus state Sen. Josh Kimbrell. On Monday, Sen. Ted Cruz visited to campaign for Wilson.

The scramble for Trump's favor stood out as the most heated element of the primary.

Even prior to the initial endorsement, Evette showcased images and clips with Trump in her materials. Mace and Norman similarly emphasized alignment with Trump's agenda.

Wilson, the state's lead prosecutor since 2011, has referenced legal filings backing the Trump administration and traveled to New York to stand with Trump during the hush-money trial that resulted in a conviction.