WASHINGTON - In an hourlong session on Monday with some of the nation's top political journalists, Gov. Tim Pawlenty laid into President Obama on everything from Afghanistan to the nation's middling recovery, making the case for how the Minnesota Republican could be the GOP's best hope for recapturing the White House in 2012.

With his presidential ambitions in full view, Pawlenty questioned Obama's leadership on Afghanistan, suggesting that arbitrary troop withdrawal deadlines are "misguided," and that the war effort may require a more open-ended commitment than the administration envisions.

Fresh from a governors' trip through Iraq and Afghanistan, Pawlenty said that "the president and the leadership of our country need to do a better job of explaining why it matters, what it's going to take, and how long it's going to take." Pawlenty made his remarks at a Christian Science Monitor breakfast in Washington. The breakfast meeting, a ritual stop in Washington politics, was attended by more than 40 writers from national media organizations, including the New York Times, the Wall Street Journal, the Washington Post and CBS.

Debuting his national policy agenda, Pawlenty endorsed the Tea Party movement and one of its top enthusiasts, U.S. Rep. Michele Bachmann, R-Minn., whom he called "a powerful, strong, clear voice for the conservative movement in this country."

Pawlenty, who has been raising money for conservative candidates nationwide, used the occasion to lay out his vision of a new crop of "next generation" GOP leaders -- including himself. He vowed to help create a new Republican tone that jettisons the stereotype of "middle-aged, white guy CEOs" who "never get their fingernails dirty."

"That's not my story," Pawlenty said, "it's not the Tea Party story, and it's not the story, really, for most Republicans."

Pawlenty, who was briefed by military leaders while in the Middle East, challenged Obama's plan to start winding down his troop surge in Afghanistan a year from now.

Arguing that American partners could start "hedging their bets" in the struggle against the Taliban, Pawlenty said, "I believe you can't put an arbitrary deadline in Afghanistan ... Seeing the corrosive effect of these deadlines reinforces my belief that they are misguided."

Pawlenty declined to lay out his own time frame for withdrawal, other than to say "the situation in Afghanistan is going to require strategic patience from the United States and our citizens."

His remarks came amid freshly leaked documents that show a grim picture of the war in Afghanistan, where the Obama administration is deploying an additional 30,000 troops. Pawlenty said that even more troops could be required.

Some of Pawlenty's sharpest criticism of Obama came on the debate over Arizona's stringent new illegal immigration law, which the White House is challenging in court.

Pawlenty said the law, which gives local police broader powers to detain illegal immigrations, had been "wildly, irresponsibly and recklessly mischaracterized, including by the president of the United States."

The White House did not respond to a request for comment.

Pawlenty highlighted his many other differences with the Obama administration, including on health care, Wall Street reform, budget deficits and the $800 billion economic stimulus plan, which the governor called "too large, too slow... [and] largely ineffective."

The governor said he would make a decision about his political future early next year.

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