The first lady draws a line between her policy efforts on childhood obesity and her political activities. But such distinctions often are lost on the public.

In an election year, it's all to the good for Barack Obama that his popular wife is traveling the country promoting can't-miss issues like healthy living and support for military families. To a more limited extent, Mrs. Obama also fills a more overtly political role by headlining private fundraisers that raise millions for her husband's campaign, reaching out to supporters through conference calls to various states and shooting out periodic emails to campaign backers around the country.

That part of her labors will increase considerably in the months to come.

For now, though, the first lady's most visible role is tied to her signature issue of fighting obesity, allowing her to connect with voters on an emotional level and relate to them as a mother who has struggled with some of the same challenges that other families face.

"We're constantly trying to make sure that what we do is on point with what is going on in people's lives," Mrs. Obama told parents this week as she chatted with them over low-calorie plates of chicken and pasta at an Olive Garden restaurant in Fort Worth. "I mean, at one point I was normal. I went to the grocery store and I did all that."

Voters typically don't pay attention to whether an event is political or not, says Democratic strategist Chris Lehane.

"They're paying attention to whether they like what they're seeing and whether they connect to it," Lehane says. And with a first lady talking about issues that transcend the partisan divide, he says, "the mere fact that they're out there talking reflects well on their spouse."

And it can't be lost on Obama's political advisers that two of the four states on Mrs. Obama's three-day tour — Iowa and Florida — will be political battlegrounds in the fall.

While the president's favorability ratings and those of Vice President Joe Biden slipped considerably over their first three years in office, Mrs. Obama's have remained strong.

Barack Obama's favorability rating now stands at 51 percent, Biden's at 38 percent. By contrast, 66 percent of Americans have a favorable opinion of the first lady, about even with her ratings on Inauguration Day, according to the Pew Research Center.

That's about where Laura Bush stood in the fourth year of her husband's first term, and it's considerably higher than Hillary Rodham Clinton's 42 percent at the start of her husband's fourth year as president.

Mrs. Obama is particularly popular with women and younger Americans, polling shows. And she does well with the moderate and liberal Republicans and independents whom Democrats will try to lure away in the fall elections.

There are other ways to measure her appeal: Her Twitter account shot up to more than a half-million followers in less than a month. And her Facebook page has more than 6.6 million "likes."

So far, Mrs. Obama has headlined 32 fundraisers over the past 10 months, including six this year. Tickets to her political events range from $100 to $10,000, making them more accessible than higher-dollar fundraisers for the president. And her political schedule includes smaller cities, such as Charlottesville, Va., and Cape Elizabeth, Maine, that aren't likely to draw a presidential visit.

Still, she's hauling in millions with a fundraising stump speech that mixes a recitation of administration policy initiatives with a personal sketch of her husband as a man who stays up late after the children are in bed fretting over the concerns of ordinary Americans.

It's the same humanizing role that Mrs. Obama serves regularly in her public appearances, as she mixes public policy with stories about her own family.

What parent wouldn't think it was cool when she confessed to her dinner guests at the Olive Garden that her daughters aren't that interested in the White House kitchen garden — "because anything I do they're not interested in."