Watching Michelle Obama speak on her first campaign trip to Pittsburgh is to observe someone who has completely mastered the art of the political stump speech after only a year of practice -- albeit with a few technical glitches at the outset.

"So I hear this is a tough mike," she said to the early afternoon crowd of 1,500 at Carnegie Mellon University's Skibo Gymnasium -- the first words out of her mouth, spoken as casually as if she were in her living room. Tall and lean and athletic-looking in a chic pantsuit, she grapples with said balky mike, which promptly slides down even further.

"Ooh," Mrs. Obama says, deadpan. "The mike is going down."

The crowd, made up mostly of students and retirees, is lapping it up as the 44-year old wife of Sen. Barack Obama delivers a series of local shout-outs, including one to Pittsburgh philanthropist Teresa Heinz Kerry, who introduces her at the rally and to whom Mrs. Obama has occasionally been compared.

Both independent-minded political spouses, they're also both known for occasionally tart-tongued, provocative statements that have sent their handlers into overdrive.

So it's perhaps not surprising that, to this Pittsburgh audience, the wife of the 2004 Democratic presidential nominee is described by the wife of the possible 2008 Democratic presidential nominee as "an exceptional mentor to me personally. You know, there are not that many people who have been through this who you can reach out to and ask 'What is this gonna be like?'

No indeed.

Nothing in Michelle Obama's fast rise to the top -- from her blue-collar childhood on Chicago's South Side, through Princeton, Harvard Law School, a top Chicago law firm, marriage to Mr. Obama and on into community service and non-profit work -- could have prepared her for this unexpected new occupation."I still can't believe it sometimes," says Paul Schmitz, who worked with her in the early to mid-1990s in Chicago after Mrs. Obama left corporate law to enter the nonprofit sector.

Hired in 1993 to be the first executive director of Public Allies, a fledgling nonprofit that recruits and trains young people to go into public service, Michelle Obama "was this woman I saw every day, who was hired to help us get our act together and did so with such competence and grace," Mr. Schmitz said.

"She loved working with young people, helping them with their strengths and weaknesses. She was really good at it. And now, she's this famous person..." he says, his voice trailing off, as though he can't quite get his mind around that fact.

Whatever self-doubts Michelle Obama harbors -- in his book, "The Audacity of Hope," her husband described "the slightest hint of uncertainty" in her "round dark eyes" -- it's not present on this day. She seems totally at ease in mingling with crowds -- rubbing a supporter's shoulder here, posing for cell phone cameras without complaint, so tactile that when she later discovers she's missing an earring she says offhandedly, "I must have hugged it off."

Mrs. Obama's visit to Pittsburgh, a day trip only, began with a luncheon Downtown at Mrs. Heinz's offices, followed by the rally at Carnegie Mellon, interviews with local media and ending with an impromptu stop at Tessaro's in Bloomfield for takeout hamburgers before heading to the airport to catch a 7 pm flight home to her two daughters.

At the very outset of her speech, the mentor-to-youth side bubbles up almost immediately:

"Where are my Students for Obama!?"

Huge roars.

"Yes we can!" She shouts back, invoking the Obama campaign's mantra before launching into a nearly 55 minute address that is part biography, part populist anthem, part rousing political brief for her husband's candidacy -- "I wouldn't be here if I didn't think Barack Obama was the person we needed right now" -- with emphasis on the word now.

"We have more pledged delegates, more of the popular vote. He's raised more money." she says to the crowd, which is stirring and applauding. "He's won more states. He's won in all kinds of states. He's won in red states, in big states, small states, blue states, swing states."

The crowd is going crazy as she delivers the punchline:

"Oh yes, and he did win the Texas caucuses."

Total meltdown.

That is about as close as Mrs. Obama gets to the much-vaunted "chip on her shoulder" attitude so frequently ascribed to her. Her jokes about her husband are relatively few -- no "stinky and snore-y" observations here -- but she does gleefully recall when he told her he would be writing a book or two to help them pay off their college loans.

"It was like Jack and his magic beans, he's like, Look honey I'm going to write these books and we'll be fine, and I'm like, yeah, sure, right."

After the speech, sitting in a small room, she is still upbeat and energetic as a parade of reporters file in and out. She talks about the relief she feels after a much-needed break in St. Thomas last week with her family, about her insistence about not being on the road every day so that she can be with her two daughters, Malia and Sasha, 9 and 7 -- " if both of us were gone for long periods of time they would start losing it."

Being a working mother is no big deal, she recognizes, since so many people do it every day.

"The truth is -- and I know people feel I'm being trite about this -- I was switching these roles before [Barack ran for president]. When you are a professional and a mother and you've got hats on, you're constantly doing this, right?"

One thing is certain: She has become much better at staying on message. She does not directly answer questions about how she feels about the Rev. Jeremiah Wright, the controversial pastor of the Obamas' church, who married the couple and whose inflammatory comments about America's treatment of blacks and of its complicity in 9/11 prompted Mr. Obama to give a much-covered speech in Philadelphia on race two weeks ago.

Rather, she dwells on how her husband handled the controversy.

"First and foremost I am so proud that Barack Obama stepped up and gave a speech that was needed," she says. "Regardless of the circumstances, this is a conversation that needs to happen, that has to happen and it hasn't happened in this country in my lifetime. It's a hot button, and Barack did it in a way that shed light, that was honest and powerful. What Barack Obama did in his speech was give voice to every emotion I have."

There will be much more moments like that, no doubt, she adds.

"This stuff doesn't happen in a vacuum. There's some hard work, and there's gonna be some tears. Change is going to be hard. It's going to require moving out of our comfort zones, away from our divisions. Letting go of fears."

At Tessaro's, she buys seven cheeseburgers (cheddar, mustard and mayo added) for $63.66 for herself and her entourage -- but not before stopping to say hello to stunned diners and waitstaff and to hug six-year old David Bertus and pose for a picture with him

She doesn't flinch when the boy tells her his father is going to vote for John McCain.

"She told me, 'Oh, that's the white-haired guy,' " young David Bertus said.

"She took the news very well," the boy's father, David Bertus, 56, of Wilkinsburg, added, with a laugh. "We liked her."