Story highlights GOP insiders in South Carolina say that each candidate has worrisome issues

Romney has been seen as too centrist, says poll

The anti-Romney vote is split between Gingrich and Santorum

Ron Paul's national security positions keep him out of mainstream, says poll

As South Carolina Republicans begin voting in the first primary of the south today, GOP insiders say that all the candidates have had their problems in Palmetto State, one reason why today's outcome has been so hard to predict.

One veteran South Carolina GOP operative summed up the dilemma of many of his colleagues in the state who are still on the fence. "For the first time in my professional life I am not working for a candidate and undecided on whom I will vote for. My heart says one thing, my mind says another."

According to a CNN survey of 46 South Carolina GOP insiders -- including state legislators, state and local party officials, business and conservative interest group leaders, veterans of previous presidential primary campaigns, Palmetto State GOP political consultants, and other party activists -- former Massachusetts Gov. Mitt Romney's biggest hurdles in South Carolina are his Massachusetts political roots and his more centrist views. Former House Speaker Newt Gingrich calls Romney a "Massachusetts moderate."

What do you think has been the biggest obstacle for Romney in South Carolina?

His record in Massachusetts -- 85%

His Mormon faith -- 13%

His role at Bain Capital -- 2%

Now that Romney wants the GOP presidential nomination again, he has moved to the right from some of his positions and the tone of his previous campaigns in the state. And that has fed the perception that Romney is willing to change his stands for political expediency. Ironically, Romney's continued defense of the Massachusetts health care reform law he helped enact as governor remains a stumbling block with some conservatives who would rather he repent on that issue.

"The two big issues that stick out to me regarding his record are his flip-flopping on abortion which many voters in South Carolina don't understand, and of course his signing of 'Romney-care,' " said one South Carolina insider. "As a result, many don't trust him and wonder if he will simply say anything in order to win the election."

And while Gingrich maintains that he's the logical alternative for conservatives, the former House Speaker's problem has been that, up until Thursday, there were two other options for South Carolina voters who were uneasy with Romney -- former Pennsylvania Sen. Rick Santorum and Texas Gov Rick Perry, who has since suspended his campaign. However, the insiders don't think Gingrich's personal issues have played as much of a factor, although they were surveyed before reports surfaced on January 19 that Gingrich's second wife said he asked her for an "open marriage."

What do you think has been the biggest obstacle for Gingrich in South Carolina?

Conservative vote is too divided among candidates -- 52%

Attacks against Romney's role at Bain Capital backfired -- 33%

The negative ads run against him -- 13%

Personal baggage (volunteered) -- 2%

"Newt's populism resonates with red-meat voters in South Carolina, but the Romney-alternative field (has been) too crowded for him to lock down a solid win here," said one GOP insider.

The other main contender for the fervent conservative vote in South Carolina has been Santorum and he shares Gingrich's problem of being one of too many choice on the right.

What do you think has been the biggest obstacle for Santorum in South Carolina?

His past record as senator on earmarks and right-to-work -- 41%

Conservative vote is too divided among candidates -- 56%

Doubts about him among Southern voters -- 2%

"The biggest obstacle for all the 'not-Romney' candidates has been in a word, 'ego,' " said one GOP Insider. "All of their egos were too big to drop out (early) and work to truly consolidate conservative voters."

But another operative noted that in a state where the Republican governor had battled with the Obama administration over whether Boeing could move airplane production from assembly lines that were unionized in Washington State to a nonunion facility in South Carolina, Santorum's defense of his opposition to right-to-work laws while he was a senator has been "awkward, at best."

Texas Rep. Ron Paul's liability in South Carolina has been the same as in Iowa and New Hampshire—his isolationist views on foreign policy and his eagerness to cut military spending.

What do you think has been the biggest obstacle for Paul in South Carolina?

His stance on national security -- 78%

He didn't spend enough time in the state -- 20%

Perception that he can't win in the general election -- 2%

"Because of this and other stands, no one takes him seriously outside of his hard-core supporters," said one GOP Insider.