"I think the emotion you hear in her voice. Her ability to really articulate personally what this really means to her and how this can impact this nation," Rogers said on CNN's "New Day." "You're hearing something from the heart. This is not made up. This is her."
Obama called recently unearthed comments by the Republican presidential nominee "shocking" and "demeaning," and below "basic standards of human decency."
"I can't believe I'm saying a candidate for president of the United States has bragged about sexually assaulting women," Obama said at a rally in Manchester, New Hampshire.
Rogers said Obama was so emotional because Trump's "ridiculous" comments resonated personally with her.
"For any woman that has experienced whether it's cat calls or your body being talked about in a negative way, you feel that pain and that hurt," said Rogers, who first became friends with Obama in Chicago. "And I think that is what she's talking about. The amount of disrespect that these lewd comments that this gentleman has made is just ridiculous."
Rogers said Obama's evolution as a first lady was on display as she hit the trail in support of Clinton because America's future is on the line.
"I think the evolution is she is the first lady of this country. And we are now at a strategic point where this nation has to make a decision and my feeling is 'Enough is enough,'" she said. "I think she said I gotta take a stand."
Rogers, who became a magazine executive after leaving the White House, said she does not know if Obama will run for public office in the future.
"You know, I don't know (if she'll ever run)," Rogers said. "But I do think that it is important that you mention -- It is a turning point."
"And I think that her voice is really a voice that people are hearing, people are listening to because it's beyond the rhetoric," she said.