Michelle Obama took veiled shots at Donald Trump during a commencement speech

First Lady Michelle Obama took veiled shots at presumptive Republican presidential nominee Donald Trump during a Friday commencement address at the City College of New York, referencing the wall he says he'd build on the southern US border and warning about leaders who "who demonize and dehumanize entire groups of people."

Democrats have been gearing up for the general election this week as primary season winds down. Presumptive Democratic nominee Hillary Clinton blasted Trump in a foreign-policy speech on Thursday, and President Barack Obama stepped into the fray this week with an economic address that also took shots at Trump.

Michelle Obama didn't name Trump during her speech, but she referenced his policies and denounced the divisiveness that's often attributed to his campaign rhetoric.

After referencing a quote from a CCNY student about the importance of diversity, Michelle Obama said, "unfortunately, graduates, despite the lessons of our history and the truth of your experience here at City College, some folks out there today seem to have a very different perspective."

She continued: "They seem to view our diversity as a threat to be contained rather than as a resource to be tapped. They tell us to be afraid of those who are different, to be suspicious of those with whom we disagree. They act as if name-calling is an acceptable substitute for thoughtful debate, as if anger and intolerance should be our default state rather than the optimism and openness that have always been the engine of our progress."

Citing her world travels, Michelle warned about what can happen "when ideas like these take hold."

"I have seen how leaders who rule by intimidation - leaders who demonize and dehumanize entire groups of people - often do so because they have nothing else to offer," she said. "And I have seen how places that stifle the voices and dismiss the potential of their citizens are diminished - how they are less vital, less hopeful, less free."

Michelle Obama also took a shot at Trump's promises to build a wall on the southern border of the US.

The first lady said:

We don't build up walls to keep people out because we know that our greatness has always depended on contributions from people who were born elsewhere but sought out this country and made it their home - from innovations like Google and eBay to inventions like the artificial heart, the telephone, even the blue jeans; to beloved patriotic songs like 'God Bless America,' like national landmarks like the Brooklyn Bridge and, yes, the White House - both of which were designed by architects who were immigrants.

And she closed the subtle anti-Trump argument with an apparent reference to him being born into wealth.

"Our greatness has never, ever come from sitting back and feeling entitled to what we have," she said. "It's never come from folks who climb the ladder of success, or who happen to be born near the top and then pull that ladder up after themselves. No, our greatness has always come from people who expect nothing and take nothing for granted - folks who work hard for what they have then reach back and help others after them."