Hillary Clinton and Sen. Bernie Sanders (I-Vt.) debate in Flint, Mich., on March 6. (Carlos Osorio/AP)

Sunday’s Democratic debate in Flint, Mich., had several memorable moments. The “Excuse me! I’m talking!” shushing of Hillary Clinton by a hand-waving Sen. Bernie Sanders (I-Vt.) was a clear stand-out. But their discussion of race was most illuminating, for it showed Sanders’s glaring inability to talk about African-Americans beyond criminal justice reform and income inequality.

Asked by an audience member about experiences they have had that helps them deeply understand the mindsets and values of other cultures,” Sanders and Clinton talked up their youthful activist resumes. The former brought up his desegregation efforts at the University of Chicago and his attendance at the 1963 March on Washington. The latter talked up her person-to-person interactions with African Americans and Latinos that started in her teenage years and continued through her work at the Children’s Defense Fund.

But it was CNN’s Don Lemon’s question about racial blind spots that magnified the gulf between the two candidates.

CLINTON: Well, Don, if I could, I think being a white person in the United States of America, I know that I have never had the experience that so many people, the people in this audience have had. And I think it’s incumbent upon me and what I have been trying to talk about during this campaign is to urge white people to think about what it is like to have “the talk” with your kids, scared that your sons or daughters, even, could get in trouble for no good reason whatsoever like Sandra Bland and end up dead in a jail in Texas.

And I have spent a lot of time with the mothers of African-American children who have lost them, Trayvon Martin’s mother. And I’ve gotten to know them. I’ve listened to them. And it has been incredibly humbling because I can’t pretend to have the experience that you have had and others have had. But I will do everything that I possibly can to not only do the best to understand and to empathize, but to tear down the barriers of systemic racism that are in the criminal justice system, in the employment system, in the education and health care system.

That is what I will try to do to deal with what I know is the racism that still stalks our country.

LEMON: Thank you, Secretary. Senator Sanders, on a personal front, what racial blind spots do you have?

SANDERS: Well, let me just very briefly tell you a story. When I was in one of my first years in Congress, I went to a meeting downtown in Washington, D.C. And I went there with another congressman, an African-American congressman. And then we kind of separated during the meeting. And then I saw him out later on. And he was sitting there waiting and I said, well, let’s go out and get a cab. How come you didn’t go out and get a cab?

He said, no, I don’t get cabs in Washington, D.C. This was 20 years ago. Because he was humiliated by the fact that cab drivers would go past him because he was black. I couldn’t believe, you know, you just sit there and you say, this man did not take a cab 20 years ago in Washington, D.C. Tell you another story, I was with young people active in the Black Lives Matter movement. A young lady comes up to me and she says, you don’t understand what police do in certain black communities. You don’t understand the degree to which we are terrorized, and I’m not just talking about the horrible shootings that we have seen, which have got to end and we’ve got to hold police officers accountable, I’m just talking about everyday activities where police officers are bullying people.

The above video cuts off before Sanders’s key quote.

So to answer your question, I would say, and I think it’s similar to what the secretary said, when you’re white, you don’t know what it’s like to be living in a ghetto. You don’t know what it’s like to be poor. You don’t know what it’s like to be hassled when you walk down the street or you get dragged out of a car.

And I believe that as a nation in the year 2016, we must be firm in making it clear. We will end institutional racism and reform a broken criminal justice system.

When Sanders said that, I tweeted, “He knows that all Black people don’t live in ghettos, right?” His answer so threw me that I didn’t even hear him say that white people “don’t know what it’s like to be poor.” Sanders’s cab story might be true, but it also struck me as rhetorical grasping at straws. And for it to be an illumination to Sanders that he doesn’t “understand what police do in certain black communities” is more damning than you think. For in this one exchange, you see Clinton’s fluency in and understanding of the language of race and Sanders’s glaring ignorance.

You also see who the true Democrat is. It’s not Sanders.

Democrats, especially those with national ambitions, know how to talk to people of color, especially African-Americans. They are the base of the Democratic Party. You learn the nuances of their concerns and the issues important to them. You take them to heart. Fail to do that and watch your political career perish. As a former first lady of Arkansas, former first lady of the United States and former Senator from New York, Clinton can speak to Blacks with a fluency that lets African Americans know she gets it and gets them.

[Why black voters remain in Hillary Clinton’s corner]

Sanders might caucus with the Democrats in the Senate, but he is a Socialist (or Democratic Socialist, as he prefers) from a state where blacks make up 1.2 percent of the population in Vermont. This might explain his shallow knowledge of African Americans compared to Clinton and his over-reliance on the hope that his messages on income inequality and criminal justice reform will trickle down from their heads to their hearts.

This is not say that all African-Americans are in love with Clinton or even trust her. Many blame her and her husband for the mass incarceration of black men that resulted from the 1994 crime bill. But just as many remember fondly the Clintons and the economic prosperity of the 1990s. And blacks are rewarding her loyalty to President Obama with overwhelming support in the primaries. Those votes are surely viewed as an electoral down payment. One that will clinch the Democratic nomination for Clinton and hopefully secure the legacy of the nation’s first black president.

That doesn’t mean Sanders’s message doesn’t resonate. It does. But it doesn’t trump other considerations. “I am not a single-issue candidate and I do not believe we live in a single-issue country,” Clinton said at the PBS Democratic debate last month. African Americans understand that better than most.

Follow Jonathan on Twitter: @Capehartj