By Deborah Charles
MILWAUKEE (Reuters) - Once wary of life on the political scene, first lady Michelle Obama is now embracing her role on the presidential campaign trail where she is more popular than her husband - or anyone else.
Obama's campaign is deploying her strategically in the close fight with Republican Mitt Romney to fire up Democratic supporters in swing states, win over independents and raise money.
Chanting supporters stood in a line for more than an hour in the heat at a high school in Milwaukee on Thursday to see her.
"Barack has said this election will be even closer than the last one," she told 2,000 party volunteers. "It could all come down to those last few thousand votes. That one new volunteer that you recruit - that could be the one that puts this election over the top."
She yelled to be heard over their stomping feet.
After the rousing 30-minute speech she switched course as she held a private meeting with victims and family of those killed or injured in a shooting rampage earlier this month at a Sikh temple in Wisconsin.
"It's my honor to be here with you," a somber Obama told temple secretary Kulwant Singh Dhaliwal and Oak Creek Mayor Stephen Scaffidi. "I'm sorry it's under these circumstances, but I am anxious to meet with the families and lend whatever support I can," she said, speaking in almost a whisper.
She was due to make another 180-degree turn and travel to Indianapolis later in the day for an essential part of modern campaigning: a fundraising event where she will ask donors to open their pocketbooks to help make sure her husband wins the November 6 election.
It was a long way from her first days as a campaigner in the 2008 election when she stirred controversy for saying that her husband's success had made her proud of her country for the first time in her life.
Conservatives criticized her as insufficiently patriotic and the brief controversy led her to recede from the limelight a bit before she got back into the fray.
She eventually become an effective surrogate for her husband four years ago, drawing big, enthusiastic crowds as she helped him make history by becoming the first black U.S. president.
With unemployment at over 8 percent, this election is tougher.
The first lady, 48, told her husband's re-election campaign officials that she would nevertheless limit her campaigning to three days a week to be able to see her daughters Sasha and Malia.
"My approach to campaigning is, 'This is the time that I have to give to the campaign, and whatever you do with that time is up to you'," she told reporters in February, describing what she told the campaign.
"But when it's over, don't even look at me," she said. "Don't look this direction. No calls, no anything."
Despite her reluctance, polls show that two-thirds of Americans approve of her, much more than her husband's approval rating of about 45 to 50 percent. Romney also polls mostly in the same range as his opponent in November.
The Republican's wife, Ann, is also well liked but she is less well known than the first lady and gets lower ratings. A poll in April gave her a 40 percent favorable rating.
High popularity is often a benefit of being first lady, said Susan Whitson, a spokeswoman to former first lady Laura Bush.
"She doesn't have a job description; she can make whatever she wants of the job," Whitson said of first ladies. "She's taken on issues she cares about. She humanizes the president. She gives that softer personal side and is able to connect with them. "
Michelle Obama has faced her share of criticism as first lady, from her fashion choices to fondness for supposedly pricey jewelry and expensive vacations.
Photos of a shopping foray to a Target store, which showed her as a normal mom, were attacked by conservative commentator Rush Limbaugh as a "phony baloney, plastic banana good time rock-and-roller optic photo op."
Her top priority, the anti-obesity push for healthier eating, sparked a round of attacks from conservatives who demanded Obama and the government stay out of their diets.
Romney himself has joined in at times, gently making fun of her organic garden on the South Lawn at the White House.
Michelle Obama, a Harvard educated lawyer, has held two dozen events with grassroots supporters in swing states over the past few months.
On Thursday she was visiting Wisconsin for the first time since Romney named native son Paul Ryan to be his vice presidential running mate.
Supporters like Mary Ertl Dettmann, who took off work to come to the rally, said the first lady played a vital role in the campaign.
"I like that she's a role model," said Ertl Dettmann. "It's so important for us in Wisconsin to show support for intelligent people," she added.
Michelle Obama visited on the day that the state's Republican party put up a ticker on its website to mark how long it had been since President Obama had visited the important Midwestern state, which voted for Obama in 2008 but which Romney is trying to win back this year.
"President Obama talks a great game on how important Wisconsin is in his race to the White House, yet hasn't set foot in the Badger State in more than six months," said Nathan Conrad, communications director for the state Republican party.
A Marquette University Law School poll this week showed Obama's lead over Romney in Wisconsin shrank to 3 points, from 5 points at the beginning of August.
(Additional reporting by Brendan O'Brien; Editing by Alistair Bell and Lisa Shumaker)