First lady Michelle Obama addressed the crowd on the opening day of the Democratic National Convention in Philadelphia July 25. (Video: The Washington Post/Photo: Toni L. Sandys/TWP)

Michelle Obama publicly endorsed Hillary Clinton for the first time during a primetime address in Philadelphia, giving her full support to her husband’s former secretary of state.

The first lady, who is one of the most popular political figures in the Democratic Party, said “in this election — I’m with her.”

“When she didn’t win the election eight years ago, she didn’t get angry or disillusioned,” Obama said.

“Hillary did not pack up and go home because as a true public servant Hillary knows that this is so much bigger than her own desires and disappointments. She proudly stepped up again to serve as secretary of state … She could have decided that she was tired of being picked apart for how she looks or how she talks or even how she laughs… Hillary Clinton has never quit on anything in her life.”

Obama did not mention Donald Trump by name, but she had a pointed critique of the Republican nominee.

“When you have the nuclear codes at your fingertips and the military in your command, you can’t make snap decisions. You can’t have a thin skin or a tendency to lash out. You need to be steady and measured and well informed," Obama said.

Obama marveled that it has been eight years since she stood before a similar crowd asking that Democrats to nominate her husband to be president. But she lamented that political discourse has become so harsh. Regardless, she urged Democrats to remain focused on keeping the White House.

“When they go low, we go high,” she said, repeating a mantra she heard as a child.

She delivered a passionate defense of Hillary Clinton — touting her “lifelong devotion to our nation’s children -- not just her own daughter – who she has raised to perfection, but every child who needs a champion.”

Speakers who came to the main stage earlier in the program, were booed at the mention of Clinton’s name and greeted with loud shouts of “Bernie!” Obama, however, received warmer treatment. Members of the crowd stood and hoisted “Michelle” signs. Delegates, volunteers and reporters filled the Wells Fargo Arena during her address, sitting in the aisles in some sections.

“When I think about the kind of president I want for my girls and for all children, that’s who I want,” Obama added. “I want someone with the proven strength to persevere. Someone who knows this job and takes it seriously. Someone who understands that the issues that a president tackles are not black or white and cannot be boiled down to 140 characters.”

Turning personal and emotional toward the end, Obama marveled at the journey of her family in the last eight years.

First lady Michelle Obama became emotional during her speech at the Democratic convention, as she spoke about the possibility of the U.S. having it's first female president. (Video: The Washington Post/Photo: Toni L. Sandys/TWP)

“I wake up every morning in a house that was built by slaves. And I’ve watched my daughters, two beautiful intelligent black young women, playing with their dogs on the White House lawn. And because of Hillary Clinton, my daughters and all of our sons and daughters, now take for granted that a woman can be president of the United States,” she said.

“Don’t let anyone ever tell you that this country isn’t great,” she added. “That somehow we need to make it great again. Because this right now is the greatest country on earth.”

She said her daughters and the nation’s children need a president “who understands the issues a president faces are not black and white.”

Earlier Monday, Clinton campaign spokesman Brian Fallon told reporters that they are eager to have Obama hit the campaign trail “as her schedule permits.”

Her remarks are an important moment in the final year of her husband’s presidency. While she has not been personally close to the Clintons in the years since their bruising 2008 campaign, her husband’s legacy now rests on the success of Hillary Clinton’s campaign.