Rep. Alexandria Ocasio-Cortez discussed the first Democratic 2020 debate in an appearance Wednesday on "The Late Show With Stephen Colbert."

When asked if she was particularly impressed by any candidate, she said Senator Elizabeth Warren "knocked it out the park," and "really distinguished herself."

She was less impressed with other candidates. She did not name them, but said some looked like high schoolers "who didn't seem like they read the book."

The second Democratic primary debate Thursday will feature Senator Bernie Sanders, who along with Warren is vying for Ocasio Cortez' endorsement.

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New York representative Alexandria Ocasio-Cortez teased some candidates in the first Democratic presidential primary debates for being like unprepared schoolkids — in contrast with Senator Elizabeth Warren, who clearly impressed her.

"I think with a debate stage this big, it can sometimes seem like a high school classroom," Ocasio-Cortez told host Stephen Colbert in an interview after the first debate in Miami.

"And there were some folks, like, who didn't seem like they read the book, and then they got called on."

She continued, without naming names: "I thought there were some candidates who didn't think they were going to get called on."

Colbert compared the debate to a speed dating event, and asked Ocasio-Cortez who will be asked back by Democratic voters for a "second date."

"I think Elizabeth Warren gets asked back," she replied, praising the progressive Massachusetts senator whose campaign has surged in recent weeks. "I think she knocked it out of the park."

"I think Julian Castro did a phenomenal job tonight," she continued, praising the Texas Democrat who served as housing and urban development secretary in the Obama administration.

Later, she didn't have much to say for underdog candidates such as Rep. Tim Ryan of Ohio or John Delaney.

"I'll be honest, I really do think that this was a breakaway night," she said. "I think Elizabeth Warren really distinguished herself, I think Julian Castro really distinguished himself. I think Cory Booker did a great job in talking about criminal justice."

She was less warm about front-runner and centrist Joe Biden, the former vice president.

"I think it's dangerous to assume that any candidate is a "safe choice,"" she said of Biden. "That if we pick one candidate that is just going to deliver an election for you."

Earlier she said she was amused by the attempts to speak Spanish by candidates including Beto O'Rourke, a Texas state Representative, accusing them of speaking "Spanglish" a mixture of Spanish and English, and remarking she "thought it was humorous, sometimes, at times."

"But it was good," she added. "I thought it was a good gesture to the fact that we are a diverse country."

Ocasio-Cortez, who is one of the leading progressive voices in the Democratic party, has so far declined to endorse any candidates in the crowded field for the party's 2020 presidential nomination, but in an interview in May said it was down to two candidates: Warren, or Senator Bernie Sanders of Vermont.

The two are currently battling for the support of the left-wing of the Democratic party and reportedly for Ocasio-Cortez' endorsement, and are neck-and-neck in polls.

"What I would like to see in a presidential candidate is one that has a coherent worldview and logic from which all these policy proposals are coming forward," she told CNN in May. "I think Sen. Sanders has that. I also think Sen. Warren has that."