The Charleston-area congresswoman was once a moderate Republican, but has more recently presented herself as a loyal supporter of President Trump.

"It's obviously going to make the race very fractious, very interesting with the potential to have a lot of unflattering portraits," a pollster told Newsweek.

Republican Rep. Nancy Mace of South Carolina is running for governor, entering a GOP primary in which competition for President Trump's endorsement — and the backing of his base of supporters — is expected to be fierce.