First Lady Michelle Obama says U.S. President Barack Obama "went high" when others "went low" regarding Republican presidential nominee Donald Trump's past assertion that Obama was not born in the United States. (Reuters)

Michelle Obama asked voters to consider the temperament of this year’s presidential candidates during her first campaign event for Hillary Clinton since endorsing her at the Democratic National Convention in Philadelphia in an emotionally stirring speech.

“When you are making life-or-death and war-or-peace decisions, a president can’t just pop off,” she said Friday at George Mason University in Fairfax, Va.

As the first lady did in her convention address, she pointedly criticized Donald Trump as a poor role model — but without mentioning his name.

“To start with, we need someone who is going to take this job seriously,” she said, describing herself as someone who has seen the presidency up close and knows what it takes to do the job. “Someone who will study and prepare and know the issues better than anyone on their team. The president can hire the best advisers on earth, but let me tell you that five different advisers will give five different [answers].”

The president has to make the call, she said. “We need someone who is compassionate . . . someone who will be a role model for our kids. . . . If a [candidate] is erratic, if [they] disrespect our fellow citizens . . . let me tell you, that is who they are. A candidate is not going to suddenly change once they get in office. . . . And at that point, it is too late. They are the leader of the world’s largest economy.”

First lady Michelle Obama campaigns for Hillary Clinton at the Johnson Center at George Mason University in Fairfax, Va., on Sept.16, 2016. (Photo by Marvin Joseph/The Washington Post) (Marvin Joseph/The Washington Post)

With 53 days until Election Day, she steadily emphasized character, alongside policy, as she especially targeted young voters, encouraging them to get involved.

Clinton’s support among millennials is soft, but such audiences are among Michelle Obama’s favorite crowds. She seemed to feed off the energy of the college students who dominated the audience. Near the top of her remarks, Obama noted that her family is “almost at the end of our time.”

“My husband’s going to need a new job. I’m going to have to find a job. We’re going to have to get the old house cleaned up so we can get our security deposit back,” she joked. The crowd interrupted her, chanting “Four more years!” for more than 20 seconds.

“You have me and Barack working on your behalf for the rest of our lives,” she said.

Although the majority of her speech focused on Clinton’s credentials, Obama couched the candidate’s vision for the United States as an extension of the progress she said her husband has made in righting the economy, extending health care and pushing for greater equality for the LGBT community.

First, she called Clinton the most prepared person in history to take on the presidency, echoing language used by her husband. “And, yes, she happens to be a woman,” the first lady added.

First Lady Michelle Obama campaigns for Hillary Clinton at The Johnson Center at George Mason University in Fairfax, Virginia. (Marvin Joseph/The Washington Post)

Then, the first lady painted a picture of the nation as headed in the right direction.

“Do you want to go back to the way things were before Barack Obama was elected?” she asked.

Obama, who came to the national stage as a reluctant political spouse, has not loved campaigning but became effective at it. Until Friday, she had not been on the political stump since her husband’s last race. But during her time in the White House, on the trail for him,she has honed the art of subtle messaging and staying out of the partisan fray.

“Being president isn’t anything like being on reality TV,” she said to cheers.

“Then, of course, there were those who questioned and who continue to question for the past eight years, and up to this very day, whether my husband was even born in this country,” Obama said, referring to Trump’s embrace of the false “birther” theory about her husband’s birthplace. “Well, during his time in office, I think Barack has answered those questions with the examples he set, by going high when they go low. And he’s answered these questions with the progress we’ve achieved together.”

In her husband’s campaigns, his aides called her “the Closer” because she would urge crowds to take the tangible actions needed to win. Speaking to donors, she would ask them to “max out.” And among students, she would elicit pledges to go to the polls and take their friends along.

She asked the crowd to do the same for Clinton, pointing to Virginia as a crucial swing state.

Young voters provided the margin of victory in 2012 for Obama in Virginia, she said.

“If you start to feel tired by all the negativity in this election, if you just want to hide under the bed and not come out, [know that] on November 8th you will decide whether we have a president who . . . believes in science and will fight climate change, or not,” she said. “You will decide whether we have a president who will honor our proud history as a nation of immigrants, or not. You will decide whether we have a president who believes women have the right to make their own choices about their bodies, or not.”

The first lady has a pattern of bookending her more partisan moments with those that are purely rooted in pop culture, and the crowd seemed to notice. Before she gave one of the most well-
received speeches of the Democratic nominating convention, she drove around with comedian James Corden for one of his “Carpool Karaoke” segments on CBS’s “The Late Late Show.” In it, she sang and talked about her work supporting girls’ education around the world.

Similarly, she started this week by co-hosting Ellen DeGeneres’s talk show — which included a wacky shopping trip through a CVS store, where the women poured cups of boxed wine for patrons. Amid the antics, Obama was burnishing her legacy and that of her husband, telling DeGen­eres that they have seen themselves as role models and have tried to “make sure what kids are seeing is something they can be proud of.”

That theme, of course, was a big part of her remarks in support of Clinton, and at one point an audience member interrupted to mention the “Ellen DeGeneres Show” appearance.

Democrats are hoping that the pop-culture cachet and star power that the first lady has built through such appearances will help turn out voters for Clinton — especially young people.