The Rev. Martin Luther King Jr. speaks at a Charter Day ceremony at Howard University in Washington in 1965. (Charles Tasnadi/AP)

Wednesday marks the end of Black History Month. And like prior Februaries, this month has seen its fair share of articles lamenting Americans’ lack of knowledge about African American history. A report by the Southern Poverty Law Center concluded that schools are not adequately teaching the history of slavery in particular.

Despite these laments, Americans remain fundamentally divided on the teaching of black history. That’s not new. What is new is the growing polarization of Democrats and Republicans on this issue.

A new poll shows the same old racial divide

In a February YouGov/Economist Poll, 85 percent of African Americans and 32 percent of whites said that there’s not enough black history in our schools. This large racial divide isn’t surprising. The last time that major polling firms asked about teaching black history, two polls in 2000 showed that African Americans were over 40 points more likely than whites to want more black history taught in schools.

But the partisan divide is new

In the February poll, Democrats and Republicans were miles apart: 67 percent of Democrats thought our schools should be teaching more black history, compared with just 10 percent of Republicans. This divide, unlike the racial divide, is more recent. The left graph below shows that in 2000, Democrats and Republicans were about 20 points apart. The partisan divide is now 57 points.

Graph by Michael Tesler. CBS News Poll, February 2000; New York Times Poll, June 2000. YouGov/Economist Poll, February 2018. Results from the two 2000 surveys were accessed from the Roper Center’s data archive and averaged together.

The graph on the right shows that Democrats and Republicans have also grown increasingly divided over whether schools are teaching too much black history. In 2000, Democrats and Republicans didn’t differ on this, and Democrats haven’t changed in the past two decades.

Republicans, however, are now 30 points more likely to say schools should teach less black history. In fact, one-third of President Trump voters in the February YouGov/Economist poll said that “American children should solely be taught about Western civilization and European/U.S. history.”

Where is the partisan divide coming from?

Several studies show that Americans’ partisanship is much more polarized by racial attitudes than it was 20 years ago. Democrats and Republicans increasingly inhabit separate realities about race-related controversies — including the Confederate flag and police brutality. Last year, 81 percent of Donald Trump voters and 21 percent of Hillary Clinton voters opposed removing the statue of Robert E. Lee from a park in Charlottesville.

As long as U.S. partisan politics is so polarized over issues of race and multiculturalism, Democrats and Republicans will inevitably differ over how the nation should value the historical contributions of white and nonwhite Americans.

Michael Tesler is associate professor of political science at the University of California at Irvine, author of “Post-Racial or Most-Racial? Race and Politics in the Obama Era,” and co-author of the forthcoming book “Identity Crisis: The 2016 Presidential Campaign and the Battle for the Meaning of America.”