WASHINGTON - After more than a year of preparation, former Minnesota Gov. Tim Pawlenty plans to formalize his quest for the presidency during a trip to Iowa on Monday.

Pawlenty has long made clear his interest in pursuing a bid for the Republican nomination in 2012, but aides did not confirm until Friday that he will formally declare as a candidate in Iowa, the first-in-the-nation caucus state that is crucial to his chances.

He is to appear at a town hall in the Iowa Historical Building in Des Moines and will be introduced by his wife, former First Lady Mary Pawlenty.

Pawlenty's entrance in the 2012 presidential race follows that of several better-known but considerably more controversial rivals, such as former House Speaker Newt Gingrich and U.S. Rep. Ron Paul.

Despite Pawlenty's low poll numbers in early primary states, he is seen as a potential consensus candidate in a GOP field made up of such well-worn names as presumptive front-runner Mitt Romney and Tea Party favorite Sarah Palin.

"He's in the top tier," said Washington political analyst Stuart Rothenberg. "He's looking increasingly formidable as every other candidate seems to screw up. I don't know how much passion he creates, but he's solid enough, substantial enough, serious enough, and he's put together a pretty good team. He might just be the guy the party settles on."

U.S. Rep. Michele Bachmann, another Minnesota Republican who is exploring a White House run, is believed to be ready to formally announce her candidacy soon, possibly within the next week. Bachmann could be expected to pull well among social conservatives in her native Iowa, overshadowing Pawlenty and complicating his hopes of doing well there. Like Pawlenty, she has been traveling extensively in the Hawkeye State, where she plans to spend Memorial Day weekend before heading to first primary state New Hampshire.

Pawlenty's Monday launch, just days ahead of Bachmann's visit, could help ensure that his long-anticipated announcement would not be eclipsed by Bachmann, whose outspoken utterances have garnered her a higher media profile.

"If she announced before he did, there'd be the big buzz about her announcing, and he would just sort of be picked up along in the wash," said Dennis Goldford, a political scientist at Drake University in Des Moines.

Pawlenty's announcement also comes as some better-known Republican heavyweights have officially pulled out. Former Arkansas Gov. Mike Huckabee, who won Iowa's GOP caucuses in 2008, has decided against a run. Mississippi Gov. Haley Barbour, a power-broker in the party's top echelons, also recently bowed out.

Iowa nearly always figures into presidential candidates' announcement plans -- often the first stop following a presidential campaign announcement in the home state. President Obama, for instance, made his bid official in Springfield, Ill., in 2007, then traveled to Iowa later that day.

"He probably figures he's going to get a bigger, better media bump doing it in Iowa than doing it back home," said David Yepsen, a former Des Moines Register political reporter who is now director of the Paul Simon Public Policy Institute at Southern Illinois University. "He needs the attention in Iowa."

Pawlenty might not have gotten much attention back home. His announcement comes on the last day of the state's legislative session, when the Republicans who control the House and Senate will be wrapping up their final bills and heading into what is a near-certain special session.

Said Goldford: "Coming here gives him a certain moment in the sun. Everything is designed to generate some buzz, and actually doing it here might get more attention here than if he announced at home."