The former first lady, 54, was greeted like a rock star at a conference called the United State of Women Summit, with an audience of some 5,000 people in Los Angeles, almost all women.
"It doesn't matter who runs," she said, urging women to act for women's empowerment wherever they can - including at home and in the workplace.
November release set for highly anticipated Michelle Obama memoir
"We don't wait for the one person to save us. We voted for Barack Obama and he didn't end racism," she said.
Obama also paid tribute to young Americans who have risen up against gun violence following the Valentine's Day shooting at a high school in Parkland, Florida that left 17 students and staffers dead.
After Obama, a Nobel prize for Trump - or not so fast?
Other speakers at the conference included actress Jane Fonda and Tarana Burke, a key figure in the #MeToo movement that arose after the flood of sexual misconduct allegations against Hollywood mogul Harvey Weinstein.
COMMENTS (1)
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ