The campaign bus rolled to a stop in an Iowa parking lot. Earlier that day, recorded phone messages had been left with supporters in Sioux County, alerting them that, while the outdoor rally would proceed, unforeseen events would prevent the candidate from appearing. About 70 people — a large crowd by Iowa standards for so early in a presidential campaign — had shown up to stand in the sweltering heat anyway.

It was the type of fervent anticipation long yearned for by backers of former Minnesota governor Tim Pawlenty, who has patiently courted Republican leaders and voters here for more than a year. But this was not Pawlenty’s bus, or his crowd. These people had come for a contender who had yet to make a single appearance in Sioux County.

A couple of minutes later, the candidate’s voice, coming from a telephone, floated out of the speakers in the parking lot. “Hi, everyone. This is Michele Bachmann,” she said, and soon the lot was filled with hearty applause.

As a critical week begins in the Republican presidential contest, the broadening perception in Iowa is that enthusiasm for Pawlenty has sagged recently, imperiling his candidacy, while Bachmann has soared to front-runner status here. There are growing doubts as well about the Pawlenty campaign’s organizational efforts, once regarded as its chief strength.

But two upcoming events offer Pawlenty the chance to rebound dramatically against the Minnesota congresswoman, to shore up enthusiasm and to show off his vaunted organization.

First, on Thursday night, the two will take part in a high-stakes debate alongside a field of rivals that will include former Massachusetts governor Mitt Romney, the national front-runner; former Pennsylvania senator Rick Santorum; congressman Ron Paul of Texas; businessman Herman Cain; and former Utah governor Jon Huntsman Jr.

Two days later will come the Ames Straw Poll, an early contest that will gauge enthusiasm and serve as a test for a campaign’s organizational skills. Anything less than a second-place finish for Pawlenty may have a dire effect on his ability to woo contributors for a campaign having difficulty securing big-ticket donors. And although some of Pawlenty’s backers think he can still win here, others do not rule out the possibility that he could sink to third or fourth place, behind Paul, Cain or Santorum.

His decline in Iowa has less to do with any policy stance than merely a hardening perception among detractors — and a worry among supporters — that he is not as charismatic or rhetorically tough as some of his rivals, particularly Bachmann.

One moment in his campaign has crystallized all the skepticism about him: In June, during a New Hampshire debate of the GOP contenders, Pawlenty — who previously had been deriding the Massachusetts health-care plan forged during Romney’s term as governor there — declined an invitation from the moderator to engage Romney on the issue.

“I think it really hurt him,” said Iowa state Sen. Randy Feenstra, a prominent Pawlenty supporter. “The question was served up to him like a softball and he just whiffed. I think people were looking for someone to come out and be a leader in that moment and he didn’t do that.”

Feenstra expresses confidence that Pawlenty will win the straw poll, promoting the candidate wherever he goes. But if Pawlenty finishes anything less than a close second, Feenstra says he will need to reassess his support. Potentially compounding Pawlenty’s problems with Feenstra and other supporters in Iowa is their fascination with the possible candidacy of Texas Gov. Rick Perry. “I am with Pawlenty,” Feenstra says. “But if Pawlenty doesn’t pick up steam, I’d be excited to see Perry run.”

Amid the warnings and gloom, Pawlenty has recently pushed harder than ever in Iowa. On the last Thursday in July, he climaxed a four-stop day by appearing in a commodious, air-conditioned room at a branch of the Sioux City Library.

In a room with 45 seats, 32 subdued spectators showed up to look him over. He talked about his vetoes of spending legislation as Minnesota’s governor and suggested there was a difference between his brand of “results” and his rivals’ talk.

“Who’s really done it?” he said, adding that voters “are tired of politicians flapping their mouths.”

The small crowd applauded warmly, a few members noting that they liked his message and easy-going demeanor. But most of them filed out of the room without speaking to Pawlenty or offering him the hope of an endorsement.

It was about 7:45, the end of a 12-hour day for him. After the audience and a television crew left, Pawlenty stood outside in the twilight, stretching his arms, looking like any man unwinding. But his consternation and concern have grown in recent weeks with all the sniping about his stylistic shortcomings. He conceded that not taking on Romney at the New Hampshire debate was a mistake. “It was a missed opportunity,” he said, tapping a half-clenched fist into his palm. “It won’t happen again.”

But opportunities have been missed in Iowa, too.

On a blistering Thursday, his determined supporter Feenstra drove to the town of Le Mars, where the annual Plymouth County fair was underway. There, the co-chairman of the county’s Republican Party, County Supervisor Don Kass, manned a Republican booth in which promotional brochures for several candidates were spread over tables.

Seeing no Pawlenty fliers, Feenstra asked about the omission.

Kass shrugged and said a field representative for Pawlenty had been late delivering the candidate’s brochures.

Feenstra winced, incredulous. “What?”

“Hopefully, we have it all out here tomorrow,” Kass said.

Near the Republican tent, supporters of Ron Paul, who had their own booth, were briskly gathering names and handing out brochures. Kass, who was using the county fair as a site for an informal Plymouth County straw poll of announced and prospective GOP candidates, eventually reported that Bachmann had won and, surprisingly, that Romney and Paul had finished a strong second and third, respectively. Pawlenty found himself in fifth, behind Cain.

Preoccupied by the missing Pawlenty fliers, Feenstra stood off to the side and shook his head ruefully. “This kind of mistake can’t happen in a campaign,” he mumbled.

In some cases, miscommunication between Pawlenty organizers and local Republican figures has spawned bruised feelings, at a cost to the candidate’s position. In Lyon County, in the northwest corner of the state, GOP Chairman Cody Hoefert was poised to support Pawlenty, despite his worry about the candidate’s New Hampshire debate performance. Hoefert had been mollified in part by assurances from some of Pawlenty’s top Iowa advisers that the candidate would attend his county party’s June fundraiser. But then, about 10 days before the event, as Hoefert recalls, a Pawlenty field representative for northwest Iowa called Hoefert to say Pawlenty wouldn’t be coming. “I lit into him,” Hoefert recounts, but was told, “The decision was made above me.”

Hoefert endorsed Santorum.

While the Pawlenty campaign labors to regain traction in this part of the state, Bachmann continues to draw large crowds, whether or not she shows up in person. The day after she spoke via phone to the Sioux County parking lot crowd, she was in a public park in the town of Spencer, in Iowa’s Clay County, addressing a crowd of about 175 enthusiasts mostly seated around picnic tables, a few of whom shouted “Michele” in greeting. She roused her admirers with short emphatic declarations and rhetorical questions.

“I love freedom,” she called out.

“Yeah,” several people howled.

“That’s what this country is about,” she went on, adding: “What’s wrong with freedom? . . . Why in the world should the people in the federal government tell us how to lead our lives?”

Pawlenty is capable of exhibiting fire, too, though seldom publicly. By the time he had reached that library in Sioux City, the questions about his low-key style had ignited his irritation. Outside as the sun fell, with his small crowd gone and the day behind him, his frustrations poured out.

“I say this a little tongue-in-cheek,” he said soberly, his 6-foot-3-inch frame ramrod-straight. “I’m an old hockey player. I’ve probably been in more fights than all these candidates in the race.”

He began tapping a reporter’s chest with a forefinger, not pugnaciously, perhaps not even consciously. He was simply trying to make a point. He settled on the number of fights he has had.

“Probably not more than a half-dozen. But I tell you: If you asked the other candidates how many times they’ve been punched in the face and how many times they’ve been in fights?” He paused. “I didn’t win them all. But, seriously, if you go into a bar, the loudest person is almost never the toughest. They’re usually just the loudest and drunkest. . . . I’m serious about that.”

He would not attach a name to the loudest person in the bar, not Bachmann’s or any other rival’s, back to being as oblique as ever. But he was still stewing. And that made him think again of Romney. He repeated that he will not squander the opportunity to engage the front-runner, if the opportunity again presents itself. Romney will be standing just a few feet away at Thursday’s debate — but so, too, will Bachmann, auditioning like Pawlenty for the role of his chief alternative.

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