5 Things to Watch in South Carolina's Republican Primary

— COLUMBIA, S.C. -- Iowa and New Hampshire did their jobs. While we started the campaign cycle with 17 Republican presidential candidates, the specter of the nation’s first two voting states has culled the field to six.

For the last 30 years, though, South Carolina voters have had a different role: to choose the nominee.

As the polls open Saturday, here are the storylines we’re following in the First in the South primary.

1. Another Trump Runaway?

While polls tightened and eventually gave way to a loss in Iowa, Donald Trump played his hand to perfection in New Hampshire: a 20-point victory over a crowded field across a variety of voter groups.

Trump may see a similar scenario play out in South Carolina, despite completely different demographics: in a state where large proportions of evangelicals were supposed to favor Texas Sen. Ted Cruz, several polls show the Manhattan millionaire beating the son of a Baptist preacher by double digits.

Trump also commands large swaths of loyal veterans -- a big plus in a state that's home to active bases for each military branch.

If Trump wipes the floor with Cruz in the Palmetto State, the question has to be asked: will he do the same across the South on March 1st in the vaunted “SEC Primary?”

2. The Nastiness Factor

The “aw, shucks” days of Iowa and New Hampshire are over: South Carolinians have a distressfully high tolerance for negative campaigning.

Late this week, residents told ABC News they were receiving more than a dozen “robo-calls” a night. A recent one, released Thursday night by the pro-Cruz Super PAC Courageous Conservative Political Action Committee, bashed Trump for encouraging the removal of the Confederate flag from the South Carolina state house.

“People like Donald Trump are always butting their noses into other people’s business,” a grave voice intones. “Trump talks about our flag like it’s a social disease.”

Negative advertisements are one thing. Genuine deception is another. Marco Rubio supporters called foul this week over an apparent Facebook post from supporter and South Carolina congressman Trey Gowdy, who abandoned the Florida senator and endorsed Cruz instead.

The post was actually from a different account that resembled Gowdy’s name -- a trick that’s par for the course in what has become one of the most contentious cycles in recent memory.

Elections officials will also be kept on their toes looking for any false information or irregularities regarding polling places. Democrats won’t vote for another week, which could sow seeds of confusion among low-information voters.

3. Bush’s Last Stand?

On Friday night, at his last event before polls opened in South Carolina, Jeb Bush’s words hung in the air.

“I want to thank you for allowing us to close out our campaign here,” he told the crowd. “God bless you.”

Ostensibly, the former Florida governor was talking about the end of his campaign in South Carolina. But could the awkward phrasing have been a sign of larger things to come?