President Barack Obama hugs First Lady Michelle Obama in the Red Room while Senior Advisor Valerie Jarrett smiles prior to the National Newspaper Publishers Association. (Pete Souza/WHITE HOUSE PHOTO)

As her husband’s reelection campaign amps up, Michelle Obama is in a perfect position to help, by cashing in on her broad popularity with the American public. But here’s the hitch: In order to remain popular, she can’t be seen as too political.

That’s the challenge the Obama campaign faces in deploying the first lady, who could well be the president’s best political asset.

The dilemma comes as campaign aides struggle to combat a dramatic drop in the president’s approval ratings, when Michelle Obama could be critical to bolstering his image as a trustworthy, sympathetic figure.

But the risk is a flashback to 2008 when Michelle Obama became, at times, a controversy, accused in one instance of being an “angry black woman” and, in a satirical political cartoon, depicted as a militant, Afro-wearing figure.

In the past three years, she has replaced that image with one of mom-in-chief and the protector of the Obama family brand. She was photographed in a ball cap and shades shopping at Target, and talked about how she sneaks out to Petco with the family dog.

And she has become a common presence in glossy magazines, with Vogue documenting her fashion choices and Better Homes & Gardens giving her a platform to describe her healthy eating initiative and her efforts to help military families.

So far, Obama is honing her campaign message before friendly crowds at party fundraisers in private residences and grand hotels. Next week, she will raise money in Texas and Louisiana and this week, she spoke at fundraisers in Detroit, Chicago and Tampa, telling audiences that she is ready for the campaign. “I’m in,” Obama said to applause. “I am so in.”

But Obama has also made clear that while the campaign will be a priority, she does not want to be drawn into partisan fights, nor does she intend to abandon the projects she has taken on as first lady.

“She will continue to speak from her own voice, and you will also see she hasn’t been interested in knocking other candidates down,” said Susan Sher, Obama’s friend and her former chief of staff. “She is genuinely … her husband’s biggest supporter so she will continue to speak from her heart about what she thinks he brings to the country .... I would be surprised if she was interested in anything that was a very specific policy issue.”

That strategy of playing it safe is intended to ensure that Obama is an asset to the campaign and that she is still able to advance her own agenda. Already, her campaign fundraising stops have been in cities where she is also holding events for her “Let’s Move!” and “Joining Forces” programs.

That combination is a way of smoothing her transition into campaign mode and protecting her popularity, said Lisa Burns, a communications professor at Quinnipiac University and author of “First Ladies and the Fourth Estate: Press Framing of Presidential Wives.”

“She knows that there are people really ready to pounce on her. She’s been through this,” Burns said. “She knows how ugly it can get and how personal it can get.”

In early 2008, Obama was slammed by critics who questioned her patriotism after she said, “For the first time in my adult lifetime, I’m really proud of my country.” And a satirical New Yorker magazine cover meant to depict right-wing fears of a potential black first lady, painted her as militant.

This time around, as Michelle Obama holds back on public political events, several spouses of the Republican candidates, by contrast, are holding their own campaign events, engaging in retail politics and slamming the president. Anita Perry, for example, has said President Obama has driven the country to “the abyss of failure and destruction,” and Ann Romney said her opposition to the president’s record inspired her to encourage her husband to run again.

Michelle Obama’s experience has taught her not to go there, Burns said, because going negative is a risk she cannot take. The first lady’s speeches include no mention of Republicans.

Her favorability rankings are higher than those for just about any figure in Washington, including her husband. Since early 2010, more than 67 percent of Americans have viewed her favorably, according to polling by Associated Press/GfK poll.

Those numbers shot up as Obama softened her image, showing a penchant for fashion and other “girly stuff” and making clear she would not parlay her law degree into the role of presidential adviser, said Katherine Jellison, a history professor at Ohio University who has studied first ladies.

“It’s always been safest if you play the loyal wife card,” said Jellison, who compares Michelle Obama’s role with that of Laura Bush, also a popular first lady and prolific fundraiser. “I’m not saying I approve, but people can forgive a lot if they know ‘oh she is just being a loyal spouse.’”

At DNC fundraisers, Obama lists the administration’s accomplishments, then describes the president as only she can: a man with an uncanny memory, who is not deterred by hard work, and who, at bedtime, tells his wife the stories of hurting Americans.

While the president has traveled the country, pressing Republicans to support his jobs bill, the first lady has refrained from joining in.

Campaign aides said her schedule on the trail next year will be set so she remains available for teacher conferences and other events for her daughters, and for her own initiatives, which include a book on the White House garden to be released in April.

“Political campaigning is probably not the first lady’s life’s passion,” said Jen Psaki, the former White House deputy communications director. But “there is no question that she will be very active next year.”

When Michelle Obama and her husband are on stage together, they tend to get a little flirty, and it is clear she warms up the cool-natured president. Last week, they made a rare joint appearance in Virginia to promote his American Jobs Act and announce an accomplishment of her military initiative. They gazed at one another, he called her “cute,” and to the amusement of the hundreds of military families in the audience, she joked that they were enjoying the day together.

“I never get to do anything with my husband,” the first lady said to laughter. “I haven’t seen him in three days. This is a nice date!”

The crowd cheered.

Presidential aides have described the effect. “You would always want the first lady” to be at events if possible, said Bill Burton, former White House deputy press secretary. “You knew that the president would be in a better mood and you knew that the event would go a lot better.”

Polling analyst Scott Clement contributed to this report.