In her debut as a commencement speaker on Saturday, Mrs. Obama evoked the struggles of California's founders - settlers and former slaves, trailblazers and immigrants - to encourage the 493 members of the school's first full graduating class to use their newfound skills to lift up those around them.
"Many of you may be considering leaving town with your diploma in hand, and it wouldn't be unreasonable," Mrs. Obama said before a crowd of 12,000 wilting in the afternoon sun. "By using what you've learned here you can shorten the path perhaps for kids who may not see a path at all. I was once one of those kids."
Clothed in a long black robe and academic regalia, Mrs. Obama spoke of her own drive to get ahead despite tough odds, recounting the challenges her working-class family faced on Chicago's South Side.
"You will face tough times. You will certainly have doubts, and let me tell you because I know I did when I was your age," she said. "Remember that you are blessed. Remember that in exchange for those blessings, you must give something back. You must reach back and pull someone up. You must bend down and let someone else stand on your shoulders so that they can see a brighter future."
When students arrived at UC Merced four years ago, there were more cows in the surrounding pasture grass than there were academic buildings in the outer reaches of Merced, about 140 miles southeast of San Francisco.
Today the university boasts the highest percentage of first-generation college students and financially needy students, and one of the most ethnically diverse student bodies in the 10-campus public system.
Now that the jubilant members of the pioneer class have earned a degree, the first lady suggested they should cement their legacy by starting after-school programs to help students succeed, working to reduce pollution or linking needy families to social services.
But many seniors were most touched by her recognition of their dogged efforts to woo her to the fledgling campus.
Students bombarded the first lady's office with letters, e-mails and even hundreds of Valentine's cards in a nonstop campaign to get her to speak at graduation.
One freshman holed up for weeks in his dorm room, making an animated video he would later post on YouTube called "We Believe in Michelle Obama."
In closing her speech Saturday, the first lady returned the favor, saying simply: "We believe in you."
That was enough to leave Yaasha Sabbaghian, the outgoing student body president who spearheaded the effort, speechless. Saturday morning, he and 17 other students who organized the "The 'Dear Michelle' Campaign" were among the first to be embraced by the first lady.
"It was surreal. It was phenomenal," said Sabbaghian, a 22-year-old cellular biology major. "She said she wanted to come be with us on this one Saturday because of our strong efforts and because of never giving up. That's what she really liked."
Mrs. Obama's visit - her first to California since her husband became president - also has served as a weekend stimulus package for the recession-battered town, whose leaders expect a windfall of about $1.1 million from the 25,000 expected visitors.
Marshall Bishop, who runs an organic restaurant in Merced's four-block-long downtown, said he would bring in $30,000 on Saturday alone due to a huge spike in dinner reservations and a special package of sandwiches, wraps and burgers made for the Secret Service.
"We're annihilated. We're doing 400 percent more than we have done at this point last year," Bishop said, amid the clatter of the lunch crowd. "Merced is normally a slow town for restaurants, and this is doing wonders."