COLUMBIA, South Carolina (CNN) -- It may be May, but it feels like July or August here in the capital of the Palmetto State. It's 84 degrees right now, four hours before the start of the clash in Columbia, officially known as the second GOP presidential debate. And while the temperature outside the Kroger Center is supposed to cool off by the start of the debate, it's expected the heat will turn up inside, as the Republican White House hopefuls face-off for the second time in a week and a half.

Among the possible story lines tonight is Rudy Giuliani and abortion. Giuliani's answer to a Roe v. Wade question in the first debate didn't sit well with a lot of abortion opponents when it appeared he was trying to play both sides of the issue. We'll see how many times he's confronted with the divisive issue tonight.

Another good story line is Mitt Romney's religion. Will he be asked repeatedly about his Mormon faith? We're deep in the heart of a conservative state, and concerns from social conservatives could be a factor tonight.

Stick around and keep your eye on the CNN Political Ticker tonight for the latest insights on the debate, before, during and after the big event.