If Americans viewed President Barack Obama as favorably as they do his wife, he’d be sitting pretty four months before election day.

Instead, he’s locked in a neck-and-neck race with Mitt Romney and deploying the popular first lady as a potent campaign asset.

“From now until November, we are going to need all of you to get out there and tell everybody you know about how Barack is on our side, fighting for the values that we believe in and the vision that we all share,” Michelle Obama told more than 2,800 people Tuesday at a campaign rally at Barbara Goleman Senior High in Miami Lakes.

“You can tell them how Barack is fighting for working families, starting with tax cuts, so folks can keep more of their income for the things they need, like gas and groceries and school clothes for their kids.”

Grassroots rallies in Miami Lakes and later at the University of Central Florida in Orlando marked Mrs. Obama’s first public campaign events in Florida this election cycle. The crowds greeted her as no less a star than the president, with her fans standing in long lines in sweltering heat to see her.

“Today is my birthday so I get to see Michelle on my birthday quite by the grace of God, that’s all, and being a volunteer,” said Juliette Love, 64, a campaign volunteer from Lauderdale Lakes.

At UCF, where more than 2,200 packed a gymnasium, retired postal worker William Saunders of Seminole County noted the first lady’s support for veterans and her ability to connect with average people.

“I think it’s because of her upbringing,’’ Saunders said. “She didn’t come from a whole bunch of money. Her father was a struggling blue-class worker, so I think she relates very well to the middle class. She is a huge asset — to the United States and to the Obama campaign.”

A May Gallup poll found that two-thirds of Americans had a favorable view of the 48-year-old first lady, while 52 percent had a favorable view of President Obama. Which explains why Mrs. Obama has been all over TV in recent months, promoting a book about the White House garden and joking around with the likes of Ellen DeGeneres and Jimmy Fallon.

But promoting healthy living and celebrating veterans is much different from overt politicking, which can turn off voters.

Former First Lady Laura Bush did few public campaign events and enjoyed favorability ratings averaging 71 percent, according to Gallup. Former First Lady Hillary Clinton, who took a leading role in crafting President Bill Clinton’s unsuccessful health care reform plan, averaged 55 percent favorability.

Mrs. Obama chose her words carefully in Florida on Tuesday, touting her husband’s values and record without criticizing Romney. She didn’t even mention the Republican nominee, though the contrast she made between her husband and his multi-millionaire rival was clear.

“Believe me, your president, Barack Obama, knows what it means when a family struggles. This is not a hypothetical situation for him,” she said. “He knows what it means to work hard because you want something better for your kids and for your grandkids. Like me, and like so many of you, he knows the American Dream because he’s lived it. And Barack wants everyone who is willing to work hard to have that same opportunity.”