That is prompting a new round of intensified fund-raising by his financial team, which had hoped by this point to be collecting money for a general election match with President Obama. The campaign is increasingly trying to quell anxiety among Republican leaders, while intently focusing on the mechanics of accumulating delegates needed to secure the nomination.  Mr. Romney’s aides said they were confident their sustained attacks portraying Rick Santorum as a Washington insider, and Mr. Santorum’s shaky debate performance in Arizona on Wednesday, had slowed their rival’s recent surge here in Michigan.  But Mr. Romney is by no means in the clear, they said, as he fights to avert a loss in the state where he was born and raised — and where less than three weeks ago he was expected to win handily, before Mr. Santorum’s surprise triumphs in Colorado, Minnesota and Missouri.  Regardless of the results Tuesday, Mr. Santorum is preparing to fight on for weeks or months, enticed by new rules that award delegates in early primaries and caucuses based on each candidate’s share of votes. “The race is going to go a long time,” he said after addressing a meeting here of Americans for Prosperity, a conservative group.  The party’s new delegate system is a major contributor to the prolonged nature of the contest, along with the advent of supportive and well-financed “super PACs” that have helped Mr. Romney’s competitors stay in the delegate hunt when their candidacies might otherwise have withered without enough cash.  For many Republicans, the question is not just whether Mr. Romney will eventually capture the nomination, but at what cost.  There is a growing sense among party leaders that the primary fight has gone on long enough and that continued attacks by the candidates and their allies have steered the conversation away from the economy and could damage the party’s prospects in the fall.  As Mr. Romney and Mr. Santorum traded a new round of sharp charges in Michigan on Saturday, some Republican leaders expressed concern about the effects of a prolonged and nasty primary fight.  “The general election prospects for Republicans certainly would be better served if more focus was spent on Obama’s policies and the failures of those policies,” said Haley Barbour, the former governor of Mississippi and a longtime party leader. “There’s still time for that, but it would improve our prospects greatly.”  Mr. Barbour was speaking at the winter meeting of the National Governors Association in Washington, where the presidential race and the alarm over its intense negativity were central topics.  Gov. Rick Snyder of Michigan, who endorsed Mr. Romney, said he was disappointed by the acrimony that had overshadowed plans to create jobs and lift the economy. “That’s what citizens care about,” he said. “They don’t like all the bickering. It does not add value.”  Gov. Mitch Daniels of Indiana said it had fed his fears that “our side might not offer a bold enough and specific enough and constructive enough — and I would say inclusive enough — alternative.” He said the Republican race would almost certainly not be settled by May 8, the date of the primary in his state.  Indeed, Mr. Romney’s campaign has warned donors and supporters that even with his victories in the coming contests, the Republican competition may very well last until at least the middle of May. They said the situation did not indicate diminishing prospects for Mr. Romney but rather was the result of the party’s delegate-allocation rules and the additional time those require for any candidate to accumulate the 1,144 delegates necessary to secure the nomination.  The acknowledgment that the intraparty competition will most likely continue into the spring would seem to sweep aside the Romney campaign’s hope that it could string together a series of early victories sufficient to claim the nominee’s mantle — symbolically, at least — and begin focusing exclusively on Mr. Obama.  Mr. Romney’s victories have come in fits and starts, leaving the party facing chatter about a contested convention this summer in Tampa, Fla., if none of the candidates have won the 1,144 delegates needed.  Gov. Paul R. LePage of Maine raised it as a possibility again in an interview on Saturday, saying that the current candidates had “injured themselves” and the party through their negativity and that delegates to the Republican National Convention should “pick a fresh face.” (Mr. Daniels, frequently mentioned as such a possible contender, unequivocally declared he would not do so on Saturday.)  Even as Mr. Santorum appealed to conservatives for support in Michigan on Saturday, his allies were already advertising on his behalf in the next round of states to vote, another indication of how the candidates are planning to keep trading punches no matter what the outcome is on Tuesday.  In interviews, Mr. Romney’s aides and supporters dismissed that notion of a new entrant, and said their campaign was built to go the distance if necessary.  “We’re just going to have to work a little harder, and this team will do it,” said Mel Sembler, a member of Mr. Romney’s finance team, adding that it would be “ready to supply whatever he needs to win this primary” campaign.  “We’re all on the telephone again,” he said, “and we’re getting it done. It’s just going to take longer.”  Reflecting the unsettled outlook, aides to both Mr. Romney and Mr. Santorum are playing down the importance of the Michigan and Arizona primaries. Those contests are preludes to the biggest day of voting in the Republican campaign on March 6, with 10 states and 437 delegates at play on Super Tuesday.  That terrain is far less hospitable to Mr. Romney than Michigan and Arizona, particularly a swath of Southern states, where polls suggest that he is trailing Mr. Santorum and Newt Gingrich. Mr. Gingrich is aggressively trying to revive his candidacy on Super Tuesday in Georgia, the state he represented in Congress.  Here in Michigan, some Republican leaders suggested that the time had come for the party to rally around one candidate, however imperfect.  “I don’t have that spark behind any one candidate at the moment,” said Anna Mouser, the Republican chairwoman in Grand Traverse County. “But we do need to decide on our nominee. Some of these primaries are dragging out months and months and months, which leaves little time to raise money, unite and go out and defeat the Democrats.”  Jim Rutenberg reported from Troy, Mich., and Jeff Zeleny from Washington. Robert Pear contributed reporting from Washington.
As Mitt Romneyâs presidential effort steps up fund-raising to meet rising costs, some Republicans are worried about the impact of an extended party contest on the November election.