As he weighs whether to jump in to the 2012 Republican presidential race, Texas Gov. Rick Perry has been dialing GOP establishment bigwigs across the country. In phone calls that sometimes stretch more than a half-hour, Perry asks the same questions:

Is the door open for a new candidate? And how wide is it open?

The answers: most definitely, and plenty wide.

A vast reservoir of the Republican Party establishment — including elected officials, donors, strategists and activists whose support fuels presidential campaigns — remains untapped, say 19 major donors, strategists and party officials in 13 states interviewed this week.

Party leaders said they are waiting to see which candidate can build and finance a national campaign, hone a strong economic message and, most of all, appear capable of defeating President Obama.

They said that although the campaigns of former Minnesota governor Tim Pawlenty and former Utah governor Jon Huntsman had gotten off to disappointing starts, they remain convinced that either can be a strong candidate and are open to backing them.

Many also had not ruled out getting behind former Massachusetts governor Mitt Romney, although broad swaths of the party are not convinced that he’s a sure bet.

“We’re looking for a convincing, compelling, dynamic, intelligent person that we feel can win,” said former Nevada governor Bob List, a member of the Republican National Committee. “That person might or might not be in the race.”

One person who does not seem to be under consideration by party insiders is Sarah Palin. Only one of the 19 interviewed for this article mentioned the former Alaska governor, who was quoted this week as saying she’s still considering a bid.

With the Iowa caucuses six months away, the 2012 race is more fluid than the 2008 presidential campaign was at this stage, when much of the GOP establishment had chosen either the eventual nominee, John McCain, or one of his rivals. This time, many establishment types plan to hold off on offering their support well into the fall.

They are most intrigued by Perry, who is regarded as a trusted social conservative with a strong economic record.

Many of Mississippi Gov. Haley Barbour’s supporters, who have largely stayed on the fence since he decided against running, are preparing to back Perry, said Henry Barbour, the governor’s nephew and a member of the RNC.

“I hope he does run,” said Henry Barbour, who said he would endorse Perry. “I’ve talked to a number of folks who were going to support Haley had he run, and a good percentage of them are very favorable to a Perry candidacy. . . . He’s got a great record in Texas, we align with him philosophically and he can win. It’s that simple.”

In New Hampshire, where Romney has a deep organization and is the favorite to win the first primary, two leading Republicans estimated that as much as two-thirds of the state’s establishment figures have not endorsed a candidate. That includes the congressional delegation, sheriffs representing the two largest counties, nearly every state senator and the state House speaker.

“It’s a huge opening for Rick Perry — huge, huge, huge,” said New Hampshire operative Mike Dennehy, who is neutral in the race and who held senior positions in both of McCain’s campaigns. “If he announces and really announces with a bang, he could gobble up a solid third of the Republican Party establishment in New Hampshire and, I do believe, nationally.”

Perry adviser David Carney said the governor and his team had called hundreds of key activists and donors in recent weeks.

“People are widely open and in some ways enthusiastic in having additional people take a dip,” Carney said. “There hasn’t even been a subtle hint about it’s going to be tough or the train’s left the station or any of those kind of key code words.”

For all the buzz about Perry, he is untested as a national candidate. If he runs, establishment figures will watch his message closely, see how he handles the scrutiny and take stock of his abilities as a retail politician. Past hopefuls, including Fred Thompson in 2008, have made hotly anticipated late entries only to quickly fade.

This year, the establishment’s indecisiveness has left a field so muddled that by standard measures the top tier is not clearly defined — although leaders limit the group to Perry, Huntsman, Pawlenty and Romney.

“The general feeling is that Superman is in the race, including the likely entry of Rick Perry, and that any one of our governors or former governors would be an excellent candidate and could be elected president,” said Fred Malek, a prominent Virginia donor.

The absence of an overwhelming front-runner has bolstered the candidacy of Rep. Michele Bachmann (R-Minn.), a tea party heroine who, many key party figures think, cannot beat Obama.

And it has dried up fundraising for GOP candidates. Romney raised $18.25 million in the past three months, failing to match his own mark from the comparable period four years ago. Yet Romney’s haul exponentially surpasses those of other contenders.

Shawn Steel, an RNC member from California, estimated that two dozen of the national committee’s 168 members are backing Romney and that most of the rest are on the fence.

“People want to be real sure they are getting behind the right guy,” said Steel, who was one of President George W. Bush’s fundraising “Rangers.” Steel said he was leaning toward Perry.

California has long been a big source of campaign cash for White House hopefuls. But even there, one party strategist estimated that an overwhelming majority of GOP donors are uncommitted.

“Almost all of the donor community is up for grabs, even those that have contributed to one or more candidates,” said Wayne C. Johnson, a Sacramento-based GOP strategist. “It’s not like it’s anybody but Romney. That’s not the case at all. The question is, is there somebody better?”

Republicans are asking the same question elsewhere. In New Hampshire, Dennehy spent the spring building an organization for Barbour. Of the roughly 25 Republicans who were preparing to endorse Barbour, Dennehy said, one has picked Romney, and the others are undecided.

Over the weekend, Perry called Ovide Lamontagne, a New Hampshire Republican lawyer who is influential with tea party activists and has been courted by most of the candidates. Lamontagne said he told Perry in a 30-minute conversation that “the race is wide open” in New Hampshire.

“There’s an opportunity for someone who’s not in to come in now, and there’s a great opportunity for people who are already in to recruit these folks,” Lamontagne said.

The conventional wisdom has been that a sizable portion of the party’s base wants to defeat Romney. Rather, the Republicans interviewed said, many in the party are satisfied with Romney but are waiting to see whether a stronger candidate emerges.

“People are for him in the same way they were for Bob Dole” in 1996, said Tom Perdue, a longtime Georgia strategist. “They’re for him, but they’re looking far over their shoulder, hoping somebody else is going to step up.”

He said that some major Atlanta donors backing Romney have told Perdue privately that they would “jump ship really fast” if Perry runs.

Ron Nehring, a former California Republican Party chairman, said “there’s a comfort level” with Perry, who appeals to social conservatives but also has one of the nation’s best records on creating jobs.

“They also see him as someone who projects strength, who’s articulate, who has a good record to run on,” Nehring said.

But Dick Wadhams, a former Colorado Republican Party chairman, said that the establishment isn’t just “sitting around waiting for Rick Perry specifically.”

“They just want to get it right,” Wadhams said, “and they’re going to be thinking with their heads in addition to feeling with their hearts.”