On the eve of the crucial South Carolina GOP presidential primary, front runner Mitt Romney's national lead is said to be collapsing. That was the way his plummeting numbers were described Friday by Frank Newport, editor-in-chief of the respected Gallup polling organization.

He made the comments during an appearance on MSNBC (see video below). “We have seen more movement, more roller coaster kind of effect this year than any other Republican primary in our history of tracking,” Newport said. “I think anything is possible. It wouldn’t be out of the realm of possibility if Romney recovers. We’ll wait and see.”

Dogged by demands to release his tax returns and under heavy fire as a "vulture" capitalist by rival and former House Speaker Newt Gingrich, Romney's national lead has slipped seven points in the last week. Gingrich, meanwhile, has been on the rise. As of Friday, Romney was ahead by only ten points nationally, 30-20 in the Gallup tracking poll.

Meanwhile, Gingrich has sprinted ahead in polling for Saturday's crucial primary in South Carolina, as the BBC reports.

Despite an ex-wife's claim that Mr Gingrich wanted an open marriage, he was 6% ahead of Mitt Romney in one eve-of-vote opinion poll.

Former Massachusetts Governor Romney, whose ratings dipped in recent days, said the race was "neck and neck".

Saturday's election is a crucial test for the four remaining candidates.

In a poll published on Friday from Clemson University, Mr Gingrich led in South Carolina on 32%, with Mr Romney on 26%, although 20% were undecided.

 

Romney had started to downplay expectations for Saturday's vote.  Stuart Stevens, a top adviser to Romney, told CNN that his candidate, indeed, could lose the election Saturday.

"Do I think we could lose South Carolina? Sure. Of course," Stevens told CNN after Thursday's presidential debate in Charleston.

"The very idea that we are sitting where we are two days before South Carolina, having won New Hampshire, having done very well in Iowa, and the question is 'Could Romney lose South Carolina,' is such an absurd question."

"The idea should be does he have a chance in South Carolina," Stevens claimed.

When it was noted that Romney had a 10-point lead over Gingrich as recently as Tuesday, Stevens shook his head.

"These things were always going to be close," he said. "I think it's very competitive. I think it's a four-way race. The whole race is very fluid."

See the MSNBC interview with Gallup's Frank Newport.