AMES, IOWA - Texas Gov. Rick Perry wasn't on stage at Thursday night's GOP debate at Iowa State University, but his orange-clad supporters in their Longhorns' T-shirts are making his presence felt in the state.

That could be trouble for Minnesota's two presidential hopefuls. Michele Bachmann and Tim Pawlenty tried to boost their campaigns by trading barbs during the televised debate, but Perry is about to land hard in the presidential race, with a same-day announcement that could instantly dull the glow of whoever wins Saturday's straw poll.

"He's from Texas, and he's a larger-than-life governor," said Ryan Rhodes, who organized a recent Tea Party bus tour through Iowa that included Bachmann.

As the longest-serving governor in Texas history, Perry, 61, brings the executive credentials that Pawlenty has used to set himself apart from Bachmann. An unabashed evangelical Christian who last week hosted a 30,000-person prayer rally in Houston, Perry also brings the social conservative passion that has marked Bachmann's run.

In true Texas style, Perry plans to take the fight right to his rivals, with a Sunday visit to Bachmann's childhood home of Waterloo. A late entry who has never run a national campaign before, Perry is seen as someone able to work both sides of the party divide: Once thought as a moderate GOP conservative in the mold of former President George W. Bush, Perry has gone Tea Party in recent years.

Already Perry's confirmation that he will announce his candidacy on Saturday has shaken up the race. A CNN poll released Thursday showed former Massachusetts Gov. Mitt Romney as the front-runner nationally, followed by Perry. Bachmann fell in the middle while Pawlenty lagged next to last, at 2 percent.

For his first speech after the announcement, Perry on Wednesday accepted an invitation to attend the Black Hawk County Republicans' Lincoln Day Dinner in Waterloo. Defending Bachmann's turf, her campaign announced Thursday that she, too, will attend.

'Everything's going crazy'

The expected candidate convergence is heady stuff for Judd Saul of the Black Hawk County Republicans, who is watching Perry's entry transform a sleepy county fundraiser into a major political event with a press contingent that now numbers more than 100, including the BBC and Al-Jazeera.

"Holy cow!" Saul said Thursday. "Everything's going crazy."

Saul said that invitations went out to the major campaigns several weeks ago, but no one showed interest until Perry jumped in. Saul said Pawlenty's campaign had cited a previous commitment.

Bachmann's decision to check Perry's advance into Waterloo signals that she intends to give no quarter. "How crazy would it be to have Rick Perry show up and campaign in her hometown, and her not show up to talk to her own people?" Saul said.

Bachmann's supporters are not waiting until Saturday to strike back. A newly formed super PAC, "Keep Conservatives United," has already launched a video that dubs Perry "Slick Rick" and accuses him of dividing conservatives. "There is an honest conservative challenging the Washington establishment, and she's not Rick Perry," the narrator says.

Officially, the Bachmann and Pawlenty camps remain stone-faced about Perry's heavy-footed entrance into the GOP nominating contest.

"We welcome anyone to the race," Bachmann spokeswoman Alice Stewart said. "We are focused on meeting the people of Iowa in advance of the straw poll."

Pawlenty spokesman Alex Conant did not respond to a request for comment.

A poke missed by no one

But nobody could miss Perry's potential poke at the eventual straw poll winner, which many GOP insiders expect will be Bachmann.

"Most Iowans would have preferred he wait, at least until next week," said GOP strategist Tim Albrecht, an aide to Iowa Gov. Terry Branstad. All the same, Albrecht said, GOP caucusgoers will appreciate the personal visit even if Perry appears to be stepping on one of their hallowed political rituals. "With the field not really set yet, they'll give him a pass," Albrecht said.

Perry is not the only potential candidate-in-waiting casting a shadow on Iowa's straw poll. Former Alaska Gov. Sarah Palin is expected to visit the Iowa State Fair on Friday, the same day Pawlenty, Bachmann and others in the crowded GOP field have visits planned.

Unlike Palin, however, Perry seems to have an institutional presence in Iowa. Among his supporters is an independent advocacy group called Americans for Rick Perry, which is drumming up a write-in campaign at the Ames poll.

Des Moines attorney Craig Schoenfeld, a staffer for the group, said that while they can't coordinate with any campaign, he does not believe Perry's Waterloo visit is aimed at Bachmann.

"There was an event on the calendar and an opportunity to talk to a lot of Iowans," Schoenfeld said. "The governor did his due diligence."

Schoenfeld's group tried unsuccessfully to get a spot on Iowa State's grounds, where already declared candidates participating in the straw poll are setting up tents and entertainment. Perry's backers will have to settle for passing out literature instead.

"It will be a low-key affair compared to Randy Travis," said Schoenfeld, making a reference to Bachmann's entertainment headliner.

The practical effect of Perry's long-rumored entry has yet to develop. Steve Deace, an influential Christian broadcaster in Iowa, sees Perry competing for Bachmann's ultra-conservative backers. While Bachmann may "outflank" Perry on the right, Deace said, "he represents the traditional alpha male that conservatives and many other voters like."

Others see a well-funded Perry as more of a long-range threat to more mainstream conservatives such as Pawlenty and Romney. "He does have some establishment appeal," Rhodes said of Perry.

One prominent Pawlenty backer, Minnesota GOP strategist Ben Golnik, sees some equivalence in the two governors' records. But in Pawlenty's favor, Golnik said, it's far easier to establish a conservative record in Texas than Minnesota.

"If nothing else," Golnik said, "this muddles the field further."

Kevin Diaz is a correspondent in the Star Tribune Washington Bureau.