NASHUA, N.H. — Few states have shaped presidential politics like Iowa, New Hampshire and South Carolina.
By hosting the nation's first presidential primaries and caucuses, the states have heaped political and financial rewards for decades on successful candidates and hastened the end for underachievers. Yet their clout may be declining in 2016.
Campaign aides and veteran political operatives expect the Republicans' next primary season to extend well beyond the first three states, thanks to an explosion of well-financed super PACs, a robust stable of candidates and changes in the election calendar that could make the 2016 GOP primary season one of the most competitive in history.
That drawn-out scenario is despite the wishes of the Republican National Committee, which recently changed rules with the aim of giving the eventual nominee a quicker and easier path to the general election.
While there is little competition expected on the Democratic side, the Republican primary is "shaping up to be the ultimate political marathon," said Phil Musser, a GOP consultant and veteran of presidential politics. He suggested candidates might not get the "slingshot effect" from early state victories that they once might have.
Ronald Weiser, former finance chairman of the Republican National Committee, agrees. "The early states are still important, but they're not critical anymore," he said. "You're not gone if you don't do well in those first couple primaries."
By nature of being first, however, Iowa, New Hampshire and South Carolina will continue to consume much of the political world's attention over the coming 11 months. Those states, along with Nevada, are the only Republican primary contests allowed next February, according to party rules that outline strict penalties for states that try to jump ahead.
Former Florida Gov. Jeb Bush and Wisconsin Gov. Scott Walker spent much of this month trekking through all three states, as did other candidates who are aggressively hiring state-based political operatives.
Bush told South Carolina Republicans their state is critical because it holds "the first big primary," a nod to a projected turnout that dwarfs participation in Iowa, New Hampshire and Nevada. Visiting New Hampshire recently, Kentucky Sen. Rand Paul predicted the primary season could "go on for quite a while," but highlighted the momentum that the early states offer.
Yet those contenders and others are laying the groundwork to continue competing even if they stumble early.
While he faces hurdles in the early states, Bush is amassing considerable resources to go well beyond the early states — both through traditional fundraising and his allied super PAC. Walker's travel schedule includes states voting later in primaries, his aides note. Paul has been organizing a political team both inside and outside the early voting states for several months.
And even before they announce campaigns, many candidates already enjoy the backing of super PACs that can raise campaign cash with no limits.
At least 10 contenders are now backed by super PACs, or related organizations, that offer a financial safety net to help replace the fundraising boost traditionally earned from strong finishes in Iowa, New Hampshire or South Carolina. Florida Sen. Marco Rubio was the latest to join the super PAC club when an ally announced plans to run the organization recently.
Presidential super PACs did not exist at this point in the 2012 campaign. Once established, they showcased the ability of a few wealthy donors to sustain underdog candidates such as former Pennsylvania Sen. Rick Santorum and former House Speaker Newt Gingrich.
Conservative donor Foster Friess, who almost singlehandedly bankrolled Santorum's super PAC in 2012, predicted an extended campaign this time because of the quality of the candidates.
"I don't expect a clear leader to emerge until after South Carolina," said Friess.
A compressed voting calendar, as well as natural geographic advantages for some candidates later on, also offers an incentive for some Republican candidates to stay in longer.
Several Southern states, including delegate-rich Texas, are expected to hold their elections March 1, when delegates will be awarded to candidates proportionally. At least three likely competitors have strong ties to Texas — its senator, Ted Cruz; the state's former governor, Rick Perry; and Bush, brother of the former governor and president.
Both Rubio and Bush have won statewide office in Florida, which is expected to hold its primary March 15, the first day that states can host winner-take-all contests. The final primaries or caucuses must be held by June 3, with a Republican presidential nominating convention set for July 18.
Candidates need to win early to show they can go the distance, says Phil Cox, executive director for a super PAC backing New Jersey Gov. Chris Christie. Still, he says, there is less incentive for candidates to drop out early than in the past.
Even Republicans in early states acknowledge the shifting landscape. But they warned candidates not to take those states too lightly.
Candidates who think they can just survive the early rounds and fight through the slog will be following "a really risky strategy without precedent," said Fergus Cullen, former New Hampshire GOP chairman. "A win here is going to mean something."
Associated Press writers Jill Colvin in Linden, N.J., Bill Barrow in Columbia, S.C., and Holly Ramer in Concord, N.H., contributed to this report.