First Lady Michelle Obama Hits the Campaign Trail for Hillary Clinton in Battleground Pennsylvania Michelle Obama returns to stumping for the Democratic presidential nominee.

PHILADELPHIA -- The objective of Michelle Obama's first of two stump speeches for Hillary Clinton in battleground Pennsylvania today was clear: hype Clinton and tarnish Donald Trump, while getting young people out to vote.

Within minutes of taking the stage at La Salle University in Philadelphia to an ecstatic, diverse and, largely, young audience of people at or near voting age, Obama moved from laughing with the crowd and cracking jokes to slamming the ongoing "birther" movement.

Refusing to mention the Republican nominee by name throughout her remarks, Obama described Trump's previous support of the conspiracy theory that her husband was not a natural-born citizen as a deceitful, deliberate lie.

Trump has since said the president was born in the United States.

"When they go low, we go high," the first lady said today.

Obama added to applause and cheers: "A president cannot just pop off and [act] irrationally."

With 40 days until America takes to the polls to vote, Democratic presidential nominee Clinton is once again deploying Michelle Obama to stump for her in the crucial state of Pennsylvania.

After a brand-new campaign ad featuring the first lady rolls out this morning, Obama spoke to students and supporters at La Salle this afternoon. From there she was scheduled to head to Pittsburgh for a second Clinton campaign event.

Michelle Obama first hit the trail to rally for Clinton earlier this month after her stirring remarks at the summer Democratic National Convention. Given her sky-high approval rating among the American people, even when compared to her husband's, the Clinton campaign clearly views the first lady as a valuable surrogate, with Clinton's even quoting her during the debate Monday night against Trump.

The first lady today echoed past concerns and criticisms of Trump's divisiveness and what she has said are her concerns about the poor example she believes he sets for the nation's children.

She also encouraged young and undecided voters to head to the polls this fall and vote for Clinton.

“Let's face it: Elections aren't about who votes," Obama said at the campaign event here today. "It’s about who doesn’t vote."