Real estate developer Pat Neal, who has given Republican presidential contender Mitt Romney about $10,000 in political donations over the years, is not the first person one might expect to see on the Elvis-blaring, megachurch-visiting, tea-partying campaign bus of Michele Bachmann.

Yet that’s where Neal sat recently on the way to a private fundraiser, chatting amiably with Bachmann after listening to her at a rally in Sarasota that attracted nearly 1,500 supporters.

“I’m here to explore,” Neal said. “She’s charismatic, and she has lots of support.”

Bachmann’s win in Iowa’s Ames Straw Poll catapulted her to the top tier of competitors for the GOP nomination, and now the Minnesota congresswoman is trying to transform her Iowa insurgency into a full-fledged national campaign. She is working to develop a major donor network and appeal to a broader audience in order to grow her base of support beyond the tea party and evangelical movements.

That donors and activists such as Neal are undecided gives Bachmann an opening that might not have existed in other years — despite Romney’s previous status as supposed front-runner and Texas Gov. Rick Perry’s rapid ascent to the top of the polls since joining the race this summer.

Nowhere is that more evident than in Florida, a crucial early-primary state and the first to represent fully the national dynamics, both politically and demographically. The top candidates are picking and choosing among some of the other early states, but they are all investing in Florida.

Romney has developed a vast donor network here, and Perry has begun assembling a formidable finance team. Jon Huntsman Jr., the former Utah governor and ambassador to China, went so far as to open his campaign headquarters in Orlando.

On a four-day swing across Florida that ended Monday, Bachmann sent the unmistakable signal that she intends to join the fray.

“People see a need for a fiscal conservative and a social conservative and a peace-through-strength national security conservative and a tea partyer,” Bachmann said during an interview on her campaign bus in Sarasota. “There isn’t an event that I don’t go to where I don’t have people come up to me who say: ‘I’m an independent. I voted for Obama. I’m going to vote for you.’ Or: ‘I’m a Democrat. I voted Obama. I’m voting for you this time.’ It happens everywhere I go, everywhere I go: Iowa, New Hampshire, South Carolina. Florida is no different.”

There was little doubt of Bachmann’s ability to generate excitement as her blue, logo-bedecked campaign bus rolled through Florida starting last Friday, greeted by throngs at nearly every stop.

In Jacksonville Beach, police blocked hundreds of supporters from entering a packed submarine shop where Bachmann led a rally.

At the Shriners hall in Sarasota, only ticketed ralliers could enter, and even they had to endure a line that snaked around the building on a scorching Florida afternoon. They shouted, “Here, here!” and “Go get ’em!” as Bachmann railed against President Obama and issued her usual promises to reduce federal spending, eliminate the Environmental Protection Agency and reduce the corporate income tax rate.

When she got to her more familiar lines (“We will make Obama a one — term — president!”), they chanted along with her.

“I wasn’t sure, but I’m pretty darn sure now,” said Debbie Tufts, 51, a real estate broker in Jacksonville Beach, who was among the dozens of people allowed into Angie’s Sub Shop to hear Bachmann.

Tufts watched and laughed as Bachmann accepted a T-shirt from the local tea party with “I See Debt People” printed on it and proclaimed to the crowd: “I know exactly which city I’m going to wear it in, too! It ends with the initials D.C.!”

“She was awesome,” Tufts said.

Bachmann faces huge challenges in Florida and elsewhere. After she won the much-hyped Ames Straw Poll, her standing in public polls, which had soared after she entered the race in June, was quickly eclipsed by Perry.

And although Bachmann’s rock-star popularity with the tea party seems only to grow — as more devotees hear her speak, glimpse her shiny bus and hearken to the campaign’s booming sound system — others view that popularity as a liability in a general election against Obama.

Bachmann has also assembled a sizable list of misstatements along the campaign trail, and some of her promises have prompted skepticism. She has pledged to bring the price of gasoline below $2 a gallon, an idea that attracted ridicule from Huntsman. On her Florida swing, she said she would turn the economy around in one fiscal quarter — and lower taxes — claims at odds, for example, with a recent Congressional Budget Office forecast that the country will not reach full employment again until 2017.

Bachmann is determined to reach a broad swath of Republican voters in Florida, and her tour through the state featured private meet-and-greets with potential donors at every stop. Still, her appeal at public rallies, though dramatic, seemed largely limited to two groups: tea partyers and evangelical Christians.

In Orlando, for instance, Bachmann delivered a sober-toned, 30-minute speech at the awards dinner of the Florida Family Policy Council. Her voice at times strained and cracking, she spoke of her religious faith and her life as a mother and foster mother, described her miscarriage and delivered a lengthy sermon on a favorite Bible passage about Mary, sister of Lazarus.

“She was phenomenal,” said Leah Ramirez, 37, a pastor from Orlando. “I expected a political speech, but that’s not what she gave. We heard from her heart, and we heard who she really is.”

Others in the room said they were impressed, too, but many in the group also liked Perry, and they cited his executive experience as governor as an advantage over Bachmann.

As for Neal, the Romney donor, he said that although he has misgivings about Romney’s ability to connect the way Bachmann can, he will probably stick with the former Massachusetts governor.

“All my friends are for Romney,” Neal said. “All the money in Florida is for Romney. I just think there’s a difference between Michele Bachmann and Mitt Romney, and that is that she can connect both on a personal level and with 1,300 people in a room. She wasn’t fancy. She was wearing sensible shoes. She danced with [her husband] Marcus on the dais. And she was human.”