Seventy-three-year-old Denise Potter had hip-replacement surgery in May, but she boarded her Memphis church’s bus Sunday and rode 600 miles to Charlotte, N.C., all the same, just to be in the same room as Michelle Obama.

Potter says she supports President Obama in part because she really loves his wife, and she knew the first lady would deliver a message well worth hearing in her opening-night speech at the Democratic National Convention. On Tuesday night, Potter wasn’t disappointed. Several times during the searing 40-minute address, which included many personal anecdotes about Michelle Obama’s life with her husband, Potter closed her eyes and wiped away tears.

She wasn’t alone. In every corner of the Time Warner Center in Charlotte, all eyes and ears were focused on the woman many considered a possible presidential liability four years ago. What a difference three and half years can make.

On a night filled with moving tributes to the iconic Sen. Edward Kennedy, a rousing show of support from Massachusetts Gov. Deval Patrick, and the inspiring story of Julián Castro, the first lady was the undisputed star, as she reminded convention-goers and the country why her husband deserves four more years.

Obama drew “oohs” and “aahs” as she stepped on the stage looking striking in a sleeveless, deep pink dress with a shimmering pewter hem. The two-tone frock accented her rose-colored pumps and highlighted her perfectly coiffed bob and hip silver manicure.

“She was exactly what I expected and she’s exactly why I love our president,’’ said Potter. “She told me what I needed to hear about him and the next four years with the realness I needed to hear with it. She keeps it real and she keeps him real.’’

Four years ago no one knew exactly what to expect from the former Michelle Robinson who hailed from the South Side of Chicago. On the 2008 campaign trail, Obama would often speak her mind in blunt terms and offered “all too real’’ examples—bad breath and stinky socks—of her husband’s personal habits at home. The Democratic masses weren’t pleased. Obama heard her critics loud and clear and appeared to turn her persona around overnight. Months before her husband took the oath of office in January 2009, she’d deftly retooled her own profile and quickly found herself listed among the most popular political figures in Washington. Her instinctive political savvy helped her sidestep many of the political landmines several other first ladies have fallen victim to. By focusing her attentions on respectable but noncontroversial issues such as support for veterans’ families and ending childhood obesity, she continued to build additional admirers and soon surpassed her husband’s approval ratings.

“No matter how frustrated I got with government and the president at times over the last four years, I always liked Michelle,’’ said Elaine Franken of Dallas.

“She seemed like the nicest woman and the most straightforward person in the White House at times,” said Franken, 37. “At first I wasn’t sure about her, but then one day I really began to admire how she carried herself and how she cared for her family and her girls.’’

The Obama campaign always understood the importance of Michelle Obama and quickly admitted as its reelection push got underway that the first lady would be a not-so-secret secret weapon. The first lady’s nearly 60 percent favorability rating was the most surefire way of reigniting passion for Obama in 2012, the campaign realized. Attendees on Tuesday night seemed to prove that theory right.

“I like Obama a lot but definitely wasn’t as passionate about him as I was four years ago,’’ said Charles Walton, 43, of Birmingham, Ala. “Things have not been as good as I thought they’d be by now. I came here to get the spirit and the excitement back for Obama, and on the first day of the convention I can say it’s already back.’’

Michelle Obama’s ease in connecting her and her husband’s humble beginnings, student-loan debts, and core values to the average American’s woes and concerns resonated through the crowd Tuesday night like bolt of lightning. Attendees nodded their heads, wiped away tears, and leapt to their feet as she detailed the hard work of her father, who suffered from multiple sclerosis, and the sacrifices of Barack Obama’s grandmother, who passed away shortly before he was elected.

“There was something so authentic about her and her message that I think it reminded me of why I voted for Barack in the first place,’’ said Sheryl Lewis, 28, an Obama supporter from Boston. “What she said is what I want to hear more of and what the country needs to hear more of to understand where we are now and where we’re going with Barack next. She told us he needed more time to fulfill his promises, and I believe her.’’

Many in Charlotte believe hearing and seeing more from the likes of Michelle Obama, Deval Patrick, and Julián Castro are exactly what is needed for President Obama to win big in November. Listening to the passionate thoughts of those who know the president well can serve as an inspiring reminder of the hope and confidence they once felt for him not so long ago.

“So much negative has been said about this president that it is so easy to be confused about what he’s doing or what he’s done,’’ said Hattie McClain, 54, a Democrat from Tulsa, Okla. “Michelle and Deval Patrick set us straight tonight. I want to keep hearing them because they can talk about the president in a way others can’t. They can sell him to people in a way he can’t do for himself.’’