Ten Democratic candidates for president debated Thursday in Detroit. (Anthony Lanzilote/Bloomberg News)

Now it’s getting ridiculous: Four debates among Democratic presidential candidates, and no questions — or serious discussion — about K-12 education.

A nod goes to Sen. Michael F. Bennet of Colorado, a former superintendent of the Denver school system, who answered a non-education question with a call to improve the public education system. His passionate plea to “fix our school system” and focus on segregated schools came in response to a question by CNN moderator Don Lemon about why he would be the best candidate to heal the racial divide in the United States.

Some candidates made passing references to universal preschool, and moderators did raise college affordability and student debt. But when it comes to K-12 public education, which many believe is the most important civic institution in the country, nada.

There have been four debates: two in June on NBC and MSNBC with 10 candidates each night; and two this week on CNN, also with 10 candidates on each night. So, what were the moderators thinking, exactly?

That education isn’t as important as health care and immigration and foreign affairs and how Democrats can win Michigan in 2020?

That prekindergarten and higher education is more important than the grades in between?

That Americans aren’t very interested in the present and future of public education and Education Secretary Betsy DeVos’s plans to change the way U.S. children attend school?

Do the moderators think the candidates all agree so they can’t spark a fight with the issue? (They don’t.)

Is it too difficult to compose questions that get at the heart of major matters confronting public schools?

How about: “America funds its public education system largely through property taxes, and federal efforts to close the gap between high-income and low-income neighborhoods have not bridged the gap. Should there be a fundamental change in the way public schools are funded?"

Or: “If the Supreme Court rules, as it may do, that it is constitutional for states to use public funds for religious education, would you take any action as president to override that decision? Do you believe it is constitutional for public funds to be used for religious education?"

Or: “Do you agree with any education move that Education Secretary Betsy DeVos has made?” Or: “What is the most damaging step Betsy DeVos has taken, and how would you change it?” Or: “Do you agree with Betsy DeVos on expanding charter schools, and if not, where is the disagreement?”

Or: “Can you name the three biggest problems facing K-12 education today, and how you would fix them?”

Or: “What is the role of the federal government in education policy?”

Well, there’s always hope that some K-12 education question will come up in the next Democratic debate. But don’t hold your breath.

Here’s the full Bennet quote on schools:

LEMON: Senator [Kamala] Harris, thank you very much. Senator Bennet, a question for you. Why are you the best candidate to heal the racial divide that exists in this country today, which has been stoked by the president’s racist rhetoric?

BENNET: Yes. First of all, the president’s racist rhetoric should be enough grounds for everybody in this country to vote him out of office. That one thing alone should be enough.

Second, Don, I want to answer your question by tagging on the conversation we were just having. This is the fourth debate that we have had and the second time that we have been debating what people did 50 years ago with busing when our schools are as segregated today as they were 50 years ago.

We need a conversation about what’s happening now. And when there’s a group of kids in this country that don’t get preschool through no fault of their own and another group does, equal is not equal. And we’ve got a group of K-12 schools that are good because families can spend a million bucks, and you’ve got the Detroit public schools that are as segregated as they were. Equal is not equal.

And let me tell you something else, Don. I believe you can draw a straight line from slavery through Jim Crow through the banking and the redlining to the mass incarceration that we were talking about on this stage a few minutes ago. But you know what other line I can draw? Eighty-eight percent of the people in our prisons dropped out of high school. Let’s fix our school system and maybe we can fix the prison pipeline that we have.