Rep. Alexandria Ocasio-Cortez sustained her criticism of President Donald Trump's immigration policies and rhetoric on Saturday, and said that what's driving his agenda is "ethnicity and racism."

The New York Democrat was speaking at a town hall in her home district of Queens to a crowd of over 200 people.

Ocasio-Cortez pointed to an incident at a pro-Trump rally in North Carolina last week when the crowd chanted "Send her back" in reference to another frequent target of the president, Rep. Ilhan Omar. The Minnesota Democrat was born in Somalia and is a naturalized U.S. citizen.

Trump, said Ocasio-Cortez, "relished" the chant. She countered the president's false narrative that he spoke up quickly to stop it.

"He said, 'Oh I stopped it immediately,'" Ocasio-Cortez said. "Roll the tape. He didn't; he kind of presided over the situation, he relished it, he took it in, and he's doing this intentionally."

"He is using racism, he is stoking white supremacy, and he is allowing, frankly, a neo-Nazi group to go off unchecked because that is a key part of 'rousing his base,'" she said.

The freshman congresswoman also pointed to Trump's tweets from last week directed at herself, Omar, and fellow "Squad" members Reps. Rashida Tlaib and Ayanna Pressley. In the tweets, fired off two days before the North Carolina rally, Trump said the progressive lawmakers should "go back" to their countries, which are "the worst, most corrupt, and inept anywhere." Ocasio-Cortez, Tlaib, and Pressley were all born in the United States.

With the tweets, Ocasio-Cortez said at the town hall, Trump "said the quiet part aloud—that was his biggest mistake."

"Because we know that he's been thinking this the entire time. But he's been keeping it in here. And this week, it went out here. When he started telling American citizens—where are we going to go? We're going to stay right here, that's where we're going to go. We're not going anywhere," she said.

At the town hall, Ocasio-Cortez also noted the deplorable conditions in migrant detention facilities. She said federal authorities' "criminalization frame has justified abuse of human beings."

She also spoke about the children who were separated from their parents last year along the U.S.-Mexico border as part of the administration's "zero tolerance" policy.

Those children will experience lasting trauma "for which we, the United States, are responsible." The kids deserve lifelong mental healthcare services, she added.

"That is exactly why we cannot allow this administration to define immigration policy within the United States," said Ocasio-Cortez. "This is something that I think is going to have to take a 9/11-style commission."

"The 9/11 commission," she continued, was "charged with the investigating and making sure they dug out every nook and cranny of what happened and how it happened in our system. And I think that that kind of study is what's going to be required in order to reunite as many children with their parents as possible."

Ocasio-Cortez also spoke to a more positive vision of what is possible, and encouraged her constituents to "create spaces of joy."

"The America that we're fighting for is loving, it is accepting, it actualizes potential," she said.

Ocasio-Cortez ended her remarks by calling on constituents to "organize, organize, organize" because what that's really about is "creating community."