WASHINGTON -- Two stunning but little-noticed political developments have turned the race for the 2008 Republican presidential nomination into a two-man sprint.

The first is that Rudy Giuliani is leading the GOP pack in South Carolina, a rock-ribbed conservative state where you would think a socially liberal Republican would not be doing that well.

The second is that while Giuliani remains the clear front-runner in all the national Republican voter polls, Mitt Romney, who trails in fourth place in the same surveys, is leading in the first four party-preference contests in January.

Both developments say a lot about the changes going on in the GOP these days and, perhaps, about the weakness of the party's conservative wing in the presidential-selection process.

Conservative-movement activists who cringe at the idea of Giuliani as the GOP's nominee have been unable to unite behind an alternative. They have talked up Fred Thompson. But the word at the grassroots is that the former television and movie actor has been something of a disappointment on the stump -- unprepared on the issues and a bit lazy, to boot.

Arizona Sen. John McCain, whom conservatives have never trusted, especially on social issues or tax policy, has been fading. All the others in the back of the pack are not considered serious candidates.

Two forces are propelling Giuliani's candidacy. First, the former mayor, who led New York City back from the Sept. 11, 2001, terrorist attacks, has staked out national security as his major issue at a time when terrorism and the war in Iraq overwhelm just about everything else.

He is seen as a tough, take-charge leader who fully understands the stakes in the war on terrorism and looks and sounds like someone who knows how to keep our country safe and win the war at the same time.

That counts for a lot among the party faithful, especially in conservative places like South Carolina.

Second, he is seen as the only Republican who can defeat Sen. Hillary Clinton, perhaps the only political figure who would unite a fractious party in the 2008 general election.

According to the latest national polls, Giuliani was ahead of the pack by an average of 27.8 percent, followed by Thompson at 22.4 percent and McCain at 14.4 percent.

But what are we to make of Mitt Romney, the far-less-well-known former Massachusetts governor who has gone through a conversion of sorts on the party's major social issues -- from abortion rights to gun control?

While pollsters and pundits alike have been focusing on the national horse race, where Romney trails with a mere 9 percent, he is leading in Iowa, Michigan, Nevada and New Hampshire -- the states that will kick off the GOP's nominating process next year.

In Iowa, Romney leads with 26 percent, while Giuliani is at 16.8 percent. In New Hampshire, Romney is ahead with 26.4 percent to Giuliani's 22.4 percent. In Michigan, Romney leads with 26.3 percent, with Giuliani at 18.7 percent. In Nevada, he is way out in front with 28 percent, followed by Giuliani and Thompson at 18 percent each.

How can Romney be leading in four of the six nominating contests in January when he is badly trailing in the national polls?

Part of the answer has to do with his business background and his skill as a venture capitalist who invested in small growing companies and built them into winners. He has plowed much of his campaign war chest into television ads in the four early caucuses and primaries and has reaped a high return on his money. His investment strategy is based on the time-tested belief that the heavy news attention and momentum he will derive from winning these first four contests will help him overtake Giuliani in the remaining primaries where the New York Republican is ahead.

"There are two schools of thought on this," independent pollster John Zogby told me. "One says that if a candidate is leading nationwide, that will help that candidate in the early states. But I'm in the old school. I think Iowa and New Hampshire are still the gatekeepers."

Zogby is skeptical of the national polls. "Sure, Rudy is best known. Why wouldn't the best known lead in the national rankings?"

But can Romney's strategy work in January?

"The political question this really poses is, Can a front-running candidate like Giuliani get pounded in Iowa, lose in Michigan and Nevada, and get beaten in New Hampshire, and not be hurt by that?" Zogby said. "I mean, that would produce some bad stories and headlines for his candidacy."

It's an unfolding scenario that has the Giuliani campaign worried, but one it believes the candidate can overcome by quick back-to-back victories in South Carolina and Florida before the heavyweight primaries on Feb. 5.