"The Obamas Get Used to Security, Rev Up for the White House" (with video)

ABC News, with video. Part Two (5:24):

Michelle Obama has landed in the headlines not for what she's doing on the campaign trail but for what she's doing off it.

Citing "increased campaign and family commitments," the wife of Democratic presidential candidate Sen. Barack Obama, D-Ill., resigned Tuesday from her position on the board of the Treehouse Foods Corp. -- a major supplier to Wal-Mart, whose labor practices her husband has strongly criticized.

It's just one of the many adjustments Michelle Obama has had to make as her husband's run for the White House gears up.

Perhaps the family's biggest adjustment has been in the realm of personal security. After unspecified threats and overwhelming crowd sizes, Obama was the first of the 2008 presidential candidates to be assigned a Secret Service detail. It's a change that the couple's two daughters, 8-year-old Malia and 5-year-old Sasha, have taken in stride.

"Well, you know, we have Secret Service detail now, which I am extremely grateful for. And people have asked, 'Well, how are the kids dealing with it,'" she told ABC's Robin Roberts. "And, the day that they started, the detail was out at the house, and the girls met everybody and they walked up to the guys and asked, 'Do you sleep, do you sit down, do you get to eat?' And then the next morning we woke up and Sasha, our youngest one, came on and said, 'Mommy, are the secret people still here?' I said, 'They're still here.' And she said, 'OK.' She called them 'the secret people.'"

Though their children know their dad might become president, Michelle Obama said they're not letting that prospect rule their lives.

"They understand that their dad is running for president & but they really aren't directly interested," she said. "We are blessed with two kids who have the personality to work with this crazy, chaotic life that we have."

She and the senator think about how living in the White House could affect their kids' lives -- and those of minority children across the country.

"We're looking at the possibility of what they will get from their experience running for president. And what a gift, to grow up in the White House, to see world leaders, to understand how the country is shaped," she said. "What a symbol that it will show to so many young boys and girls out there, particularly kids of color, who have never seen themselves -- in a major way. What a statement that'll be."

Proving Preconceived Notions Wrong

Michelle Obama first met her husband at a Chicago law firm, where she was assigned to be his senior adviser. Though she's quick to point out she wasn't his boss, there was a spark.

"Because I went to Harvard and he went to Harvard, the firm thought, 'Ah, we'll hook these two people up.' So, you know, there was a little intrigue," she said. "Although I must say that Barack, about a month in, asked me out. And I thought no way, this is completely tacky. & It took about a month or so for him to talk me into going out on a first date."

Barack Obama was a Renaissance man on that first date.

"He was trying to sort of show all his sides. So, we went to the Art Institute in Chicago. We walked along Michigan Avenue and talked. And then we went to see 'Do the Right Thing.' So, I saw that he was down," Michelle Obama said. "I knew that I liked him a lot. He was cute and he was funny and he was charming, without, you know, being arrogant. Just a good guy."

The ease with which he connected with people as both a downtown attorney and a community organizer on Chicago's South Side was what really won her over. Michelle Obama admitted she had preconceived notions about her biracial, Hawaii-bred husband, but she said that once she got to know him, all were proved wrong.

"I was wrong. Like many people who make assumptions about -- whether it's Barack or the person in another city or down the street -- we do that as people in this country. We label. We put people in boxes. And most of the time we're wrong," she said. "And it's really the experience that you have to have with someone, the conversation, the connection. And I was able to do that with Barack, and I fell in love with him."

That deep connection has forged a strong partnership, one that Michelle Obama said keeps them grounded in their personal lives and ready for whatever the future might bring.

"We've both brought our unique experiences to this thing that we call our family. So I bring the stability piece, but he brings that sort of 'Let's try this big thing, and wouldn't this be wonderful, and look at what we could do, and let's not be afraid,'" she said. "And I like that balance."