CHARLOTTE, N.C. — Michelle Obama is as comfortable talking about policy as the warm cuddly stuff, as she proved once again in a phone conversation with several women journalists Tuesday afternoon.

Four years ago, her speech in Denver introduced her family to the nation and the nation liked what it saw. She is one of team Obama’s most popular members and powerful assets, so a lot is riding on her Tuesday night prime-time address.

What is she going to talk about? “My job tonight is just going to be to remind people of who my husband is,” the first lady said. “Even though he’s a very likable president, he has been the president, and he’s had a very serious role and there are few times when he can really let his hair down. ... Sometimes it’s important for people to remember who this man is in terms of his values and his convictions and his character.”

That’s really the important message for Democrats. The first lady can cut through the clutter of partisan labels – as well as fringe birther notions – that attempt to portray the president as something other than truly American and try to push him out of the partisan frame. And she can bring him down to earth as someone who, because of those values and his family background, can relate to Americans even as they express frustration with the slow economic progress under his leadership.

It’s a tough task, though Michelle Obama is a deft spokesperson. She advocates for her husband without tearing down the other guy – in this case, GOP nominee Mitt Romney. Ann Romney has chosen to go on the attack, calling her husband “the grown-up” in the race and calling out minority constituencies for their failure to vote sufficiently Republican. The first lady, who is still occasionally labeled angry for no reason, couldn’t try that approach if she wanted to.

Her comfort zone is making the specific universal, as when she described her reaction on the day the Supreme Court upheld the Affordable Care Act. She was traveling with staffers, she said, some young women with preexisting conditions worried about their ability to get insurance in the future.

“I wanted to give Barack a call,” she said, to congratulate him. “I thought it would be a high-five moment,” but she said his reaction was “typical, very calm, very level-headed.” She recalled her husband saying it wasn’t about politics but about the stories of families “we heard, he heard along the way.”

“It’s part of the reason why I love him,” she said, “because he never loses sight of what’s at stake and who he’s really working for.”

Expect more of that Tuesday night, policy talk that segues into family anecdotes. You may hear about the two daughters she and the president are anxious about as they enter a new school year. There might be a mention of the Lilly Ledbetter Fair Pay Act and how it helps the economic success of the women who are breadwinners for their families.

“Both of our upbringings have affected who we are as people today,” Michelle Obama said in a family story we heard in Denver that will be highlighted again, about her father and his mother and grandparents. “We get lost in the political back and forth,” she said, and “forget that in the end, there are real people whose lives hang in the balance.” She said her husband never loses sight of that, though “there are times those around him do.”

On message and with a vision of what she needs to do Tuesday night, Michelle Obama may be the best politician in the family.

Mary C. Curtis, an award-winning multimedia journalist in Charlotte, N.C., has worked at the New York Times, Charlotte Observer and as national correspondent for Politics Daily. Follow her on Twitter: @mcurtisnc3.