WAUKEE, Iowa – Who is Sen. Barack Obama’s closest adviser? Not his wife, says Michelle Obama.

“We have very separate professional relationships, which is, I think, healthy,” Michelle Obama said Monday during her fourth visit to Iowa to campaign for her husband’s bid for the Democratic nomination for president.

“There is so much work we need to do as a family and as a couple. We talk about our work, we talk about what we do, but he makes his decisions on his own and I try to be supportive,” she said.

Democratic candidate John Edwards and Republican candidate Rudy Giuliani are among the White House hopefuls who have described their wives as close advisers. Asked if she considered herself her husband’s chief adviser, Michelle Obama replied, “No, I consider myself his wife.”

A Harvard-trained lawyer like her husband, she said her main role in the campaign is to offer a personal view of her husband, an Illinois senator.

“I’m really trying to make sure people understand who Barack is from the person who knows him best, giving people a sense of who we are,” she said.

Michelle Obama said she and her husband have outgoing personalities that mesh well with campaigning in key early states, where grass-roots and up-close appearances are key.

“I love coming to Iowa and New Hampshire,” she said. “We have the kind of personalities where we really enjoy meeting people and connecting with people.”

She acknowledged, though, that the race is in its early phase.

“It hasn’t really been stressful for me yet because I really enjoy it,” she said. “Who knows how, when this thing really speeds up, how I’ll feel.”

Their young children, ages 8 and 5, limit her campaign activity, she said.