More of Democratic presidential candidate Sen. Bernie Sanders' racial blindspots are showing.

During a CNN debate on Sunday night, Sanders said that white Americans don't know "what it's like to be living in a ghetto and to be poor" — assuming that all black people lived in ghettos and were poor, which is a gross misunderstanding of how racism in America actually works.

But when NBC News asked Sanders to elaborate on his comments, he dug himself into an even deeper hole. "What I meant to say, is when you talk about ghettos, traditionally what you're talking about is African-American communities." Which, again, is wrong. Not all of black America is poor, and racism works across the spectrum of class.

Sanders has won over many young Americans with his ambitious plans for economic populism, but many critics have pointed out that his ideas lack nuance, particularly when they come to race.

"You can't talk about inequality, you can't talk about the usurpation of control and the wielding of power by an elite minority, and not mention race. You just can't," Anat Shenker-Osorio, an expert on progressive messaging, told RH Reality Check. "Otherwise you're not actually talking about it."

So far, Sanders isn't exactly helping his case.