COLUMBIA, South Carolina (CNN) -- In the summer of 2006, when Sen. John McCain was the early front-runner for the Republican presidential nomination, he began assembling what was supposed to be an unparalleled political organization in South Carolina.
Arizona Sen. John McCain gets off his "No Surrender" bus at a campaign stop in Waterloo, Iowa, Wednesday.
The Arizona senator got an early jump on the endorsement game, locking up scores of supporters, from statehouse leaders on down to mayors and county GOP chairmen.
He also began signing up many of President Bush's supporters from 2000 -- the very same people who worked forcefully to halt McCain's New Hampshire primary momentum and put an end to his presidential bid in this state.
One year and one massive campaign shake-up later, there are whispers in the state capital that some of those backers have considered abandoning McCain, perhaps to sign up with former Tennessee Sen. Fred Thompson or even former Arkansas Gov. Mike Huckabee.
"South Carolinians like presidential candidates who build support among elected officials," said Tucker Eskew, who helped engineer Bush's South Carolina primary victory in 2000, but is not affiliated with a candidate in the 2008 campaign. "But they show interest in winners, too. They want a connected winner."
McCain's endorsements -- more than 250 of them, according to a campaign spreadsheet -- are still there. But whether they are solid or soft is an open-ended question.
Many Republicans in South Carolina are currently enamored with Thompson's star power and Southern accent. Other GOP voters are waiting to see if former New York Mayor Rudy Giuliani can move beyond name recognition and maintain his front-runner status despite his progressive views on certain social issues.
Then there is McCain, his campaign hampered by financial woes and the ire of conservatives fuming over his support for this summer's failed immigration reform bill.
Once the presumptive nominee, he now trails Giuliani and Thompson in state polls.
"McCain approached South Carolina with the strange combination of trepidation, based on his previous defeat here, and a sense of entitlement with the expectation that this was his year to cruise to coronation," said Scott Huffmon, a political scientist and pollster at Winthrop University. "He had the early leads by default, but his support always seemed to come with a shrug. Once some supporters found anything to latch onto with other candidates they began a slow abandon."
But as McCain prepares to return to South Carolina this weekend on his "No Surrender Tour," political observers, Republican operatives and elected officials around the state agree it would be a mistake to write him off with just over four months to go until the primary. Despite all of his recent troubles, McCain's military record still commands enormous respect here, and there are signs that he is still very much a factor in the primary.
Poll numbers show that McCain, while no longer the front-runner, is very much within striking distance. Unlike polls in Iowa and New Hampshire that show former Massachusetts Gov. Mitt Romney leading the Republican pack, the numbers in South Carolina largely mirror national poll numbers, suggesting that South Carolina's Republican voters still are undecided and are making choices based on name recognition or national media coverage.
"The undecided [voters] here make room for a Fred Thompson or Giuliani or a McCain or anybody," said Katon Dawson, chairman of the South Carolina Republican Party. "There's not a clear winner yet. For anybody within 10 points across the top of the polls, that's fertile ground for anybody who can approach the undecideds with a vision of, 'Can you beat the Democrat and have the veto pen to beat the Congress?' "
The McCain campaign says that among the three early states, South Carolina may boast their strongest and most organized operation. Although the campaign here lost several staffers and key local endorsements as a result of this summer's turmoil, the fact that McCain emerged from the bad headlines without losing many of his state endorsements is a positive sign in itself.
This month will provide the real test of supporter loyalty. It will take at least a month before Thompson's impact on the race here is truly known, but the former Tennessee senator could siphon off support from McCain if he gains traction.
There are also the money issues. The Federal Election Commission's third quarter fundraising period ends on September 30. If McCain has another mediocre showing, he might request federal matching funds for the primary. That would put him at a financial and symbolic disadvantage against wealthier rivals like Romney and Giuliani.
At the same time, the campaign has a well-equipped fundraising network in place in South Carolina and around the country. Although the Palmetto State is not a traditional donor powerhouse, McCain raised $171,000 in the state in the second quarter, more than any other candidate in South Carolina, Democrat or Republican.
"If Senator McCain can keep his [state] leaders convinced he can win, and if he can convince the public that he's got not just leadership but momentum, South Carolina could still be in play for him," Eskew said. "He's lost momentum and money and media they need to recover. You can bet they are scrambling to do it."
After a strong performance at the Republican presidential debate in New Hampshire one week ago, the McCain campaign sees the coming weeks as the right time to build that momentum while recovering some of the independent spirit that fueled the campaign in 2000.
"We aren't running a traditional campaign anymore," said B.J. Boling, McCain's communications director in South Carolina. "I think the [campaign] shake-up ... It is something that is in the past, that we have dealt with. Our campaign in strong because of it, and we're moving forward."
McCain's bus tour is emphasizing his vigorous support for the war in Iraq and American troops overseas. In South Carolina, the "No Surrender Tour" will consist mostly of campaign stops in McCain-friendly territory: Veterans of Foreign Wars and American Legion halls, as well as a grand finale at The Citadel, where the former POW is sure to get a rousing reception from fellow veterans.
According to a Los Angeles Times/Bloomberg poll out Tuesday, 35 percent of South Carolina Republicans say McCain, more than any other candidate, is best equipped to handle the war in Iraq.
McCain will also travel through the coastal areas of the state, from Myrtle Beach down to Charleston, where he remains popular. He defeated Bush in several coastal counties in 2000.
"This is McCain country down here," said Bill Rauch, the mayor of Beaufort, who has endorsed the senator. "There are Marines in this town, and they understand what's going on in the war."
As in 2000, McCain runs into problems in the conservative upstate, home to the majority of the state's Republican primary voters. The churchgoing, socially conservative Republicans in the Greenville-Spartanburg area still don't quite trust McCain after his last presidential run and his subsequent criticisms of religious leaders.
The debate over illegal immigration this summer opened up old wounds. At a Republican straw poll held in Spartanburg in March, McCain finished in first place. As the immigration debate got under way in the spring and summer, and as other candidates gained steam, support for McCain dropped markedly.
"You can see that McCain's campaign is very quickly slipping off the radar screen," said Rick Beltram, chairman of the Spartanburg County GOP. "Thompson has at least temporarily taken some wind out of the room and that puts McCain further down on the list."
Beltram and others see McCain's fate tied to that of South Carolina Sen. Lindsey Graham, a McCain supporter and close Senate ally who also is suffering locally from his support of the immigration bill. Many say that if Graham can rebuild his reputation among conservative activists heading into his re-election campaign next year, it could pay dividends for McCain in the state.
While McCain has a difficult road ahead in South Carolina, Lou Nolan, the chairman of the Richland County Republican Party, thinks McCain can hit his stride simply by doing what many say he does best: talking to people.
"He needs to be visible," said Nolan. "He needs to go into the areas where he may not be considered a popular candidate. He needs to go out and be with the people and bite the bullet." E-mail to a friend