AOC kicked up a firestorm Tuesday when she said, "The United States is running concentration camps on our southern border" ... while discussing the controversial detention centers for illegal immigrants. She'd heard the backlash all day -- from people like Liz Cheney -- by the time we spoke to AOC Tuesday night as she was leaving Capitol Hill.

The freshman Congresswoman was undeterred and fired back at Mrs. Cheney, in particular. She went on to defend her words ... saying, "The academic definition is targeting a community and putting them in detention camps without a trial and that's what the government is doing."

That definition isn't quelling the controversy. Even House Speaker Nancy Pelosi fielded questions about it Wednesday morning, and cautioned AOC and all Democrats to beware of enemies trying to exploit their words.

Of course, the criticism of AOC's remark is that it was incredibly insensitive, and dismissive of the fact 6 million Jewish people were killed in concentration camps.