WASHINGTON - Matching up on a national stage for the first time since they both set their sights on the White House, former Gov. Tim Pawlenty and U.S. Rep. Michele Bachmann will woo activists at this week's influential Conservative Political Action Conference.

Interest in the two Minnesota Republicans has sparked since Bachmann let slip her presidential ambitions just as Pawlenty was embarking on a book tour to raise his national profile.

A much-awaited CPAC straw poll Saturday will clarify how much traction the two have gained with the party faithful. It will include 15 of the potential GOP presidential field and represents the first national forum pitting Pawlenty and Bachmann in a head-to-head contest a full year before the first 2012 caucus.

The 11,000 people expected to attend the CPAC this year make up the "shock troops" of any future Republican campaign, said David Keene, chairman of the American Conservative Union, which organized the conference. "It's important at a very early stage to know how the activists feel."

The turf is a familiar one for Pawlenty. The 6 percent he drew in last year's straw poll put him fourth, behind potential GOP contenders Ron Paul, Mitt Romney and Sarah Palin, in that order.

Bachmann has attended the conference before, but not as a presidential hopeful. In their only other matchup to date, Pawlenty finished third in last month's straw poll of New Hampshire Republicans. Bachmann was close on his heels in fifth place. Romney, the top-seed in the GOP field, was the clear winner with 35 percent of the vote.

Since then, the two Minnesotans have been crisscrossing the nation for new adherents.

Pawlenty, capping a meticulous, yearlong rollout of his presumptive candidacy, addresses the convention on Friday afternoon, fresh from the latest of a half-dozen swings through Iowa.

Bachmann will be there one day ahead, opening the conference as its keynote speaker on Thursday morning. She pushed herself higher on the national stage last month with an unofficial rebuttal to President Obama's State of the Union address that was carried live on CNN. She recently made appearances in Iowa, Hawaii and Montana.

The challenge for both Minnesotans will be to inspire a ballroom full of social conservatives who might not have seen them before in person.

Keene said Bachmann carries an advantage. "She's sort of a rock star among the young Tea Party-oriented people in the party," he said.

That, along with her record-breaking $13.2 million fundraising haul in the last election, has the party buzzing about whether the iconoclastic congresswoman could eclipse Pawlenty, a less outspoken figure who has been working overtime to get media and popular attention.

"Pawlenty has said all the right things, but let's be honest, having a fellow Minnesotan in the race will complicate things for him," wrote Craig Robinson, a former Iowa GOP official who now runs the state's largest conservative news site, TheIowaRepublican.com. "When that first poll comes out that shows either of them trailing the other it will be a major blow to whoever comes up short."

Robinson also called a potential Bachmann run "a perfect storm in Iowa."

But not everyone thinks Bachmann will necessarily take CPAC or Iowa by storm.

"Yes, you have to be a credible social conservative" to do well in Iowa's influential GOP caucuses, said David Yepsen, a former political reporter for the Des Moines Register who now directs the Paul Simon Public Policy Institute at Southern Illinois University. "They feel strongly, but they want someone who can win. There's a real streak of pragmatism there."

'Presidential test'

Bachmann's penchant for provocative gaffes, exaggerations or misstatements may have deepened her allure among fans who see her -- and themselves -- as victims of Washington establishment elites. But that reputation also could test her credibility among GOP activists keen on finding a candidate who can take on Obama.

In contrast to Bachmann's colorful media personality, Yepsen said, "Pawlenty almost makes a virtue out of being a little bland and boring, which in the great scheme of presidential campaigns is not all bad."

In any showdown with Bachmann, a bigger issue confronting Pawlenty is the lack of a strong political brand. A recent New York Times graphic shows the GOP field along two dimensions: moderate/conservative; and insider/outsider. It depicts Bachmann as a firm conservative outsider. Pawlenty falls squarely in the middle.

"He has to be frustrated beyond heck at this point," said Hamline University political scientist David Schultz. "He has not figured out a way to crack through, and then immediately Bachmann has all the buzz."

But for all the media attention, Bachmann has been far less committal about her intention to actually enter the race. "I have no idea if Michele Bachmann is going to run for president," Keene said. "And neither does she probably."

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