Ron Paul could be Santorum’s stumbling block in South Carolina primary

How Rick Santorum handles Ron Paul’s attacks could determine whether he can win in South Carolina.

Santorum and Paul have long been at each other’s throats, fighting vigorously over foreign policy and Iran since June’s GOP debate. While attacking Paul may have helped Santorum get more time at the debates when he was in the second tier, once he emerged as a first-tier candidate he stayed engaged in the back-and-forth with Paul, complaining about robo-calls Paul backers were making in Iowa hitting him on gun rights.

Santorum appears at times to hold a personal grudge against Paul.

“Ron Paul is disgusting,” he said the day of Iowa’s caucuses.

That friction kept up in New Hampshire. During last weekend’s debates, Santorum called Paul “dangerous” on foreign policy and “ineffective” at passing legislation. Paul, in turn, called Santorum “corrupt.”

Santorum has been hovering around 15 percent in polls of South Carolina in the last week, trailing Romney and Gingrich by five to ten points in most of the polls and tied with Paul, who is running ads in the state slamming Santorum as a “serial hypocrite” who voted to raise the debt ceiling.

If Santorum can effectively dismiss Paul’s attacks and focus on Romney, he could finish strongly in South Carolina. But if he keeps getting drawn into under-card matches with Paul he will struggle to be seen as fighting in the main event.

Paul’s supporters have heckled many of the other GOP candidates at events, but seem to have it out for Santorum more than the others. In Iowa, Paul supporters snuck into Santorum events to press him on issues including his vote for the No Child Left Behind law which centralized education spending.

At one Santorum stop at an Iowa Pizza Ranch, a Paul supporter with “Ron” and “Paul” written on the backs of his hands asked Santorum for a photo and flashed a thumbs-up sign. At a high school event featuring both candidates the next day, Paul backers chanted “Big-spending Rick” as Santorum exited the event, drowning out his conversation with reporters.

In New Hampshire, he was surrounded by a combination of Paul and Occupy Wall Street protestors, leading to a scuffle as he tried to make his way to his car.

Paul’s crowds may not be as large in South Carolina — he has spent much less time building his infrastructure there and the state’s large military population and social conservatism may make it hard for him to make the same types of inroads there. But he and his backers will likely remain a problem for Santorum. How the former Pennsylvania senator handles the heat could determine how well he does in the state.