Can you name the most contentious issue in American politics?

Here’s a hint. It’s being fought at the federal, state and local levels. And it doesn’t go away. The struggle is persistent, ongoing, unending.

Here is a second hint. The issue is not gay marriage, or gun control, or police brutality and or immigration. Those issues are either settled, largely settled, isolated or completely out of the control of local and state governments.

Here is a third hint. The issue divides Republicans and Democrats, conservatives and liberals. But it is especially divisive among Democrats and among people who call themselves “liberal.”

Give up?

The most divisive issue in American politics is: What should we do about the education of children from low income families?

To appreciate how divisive the issue is among Democrats consider that Bernie Sanders can’t talk for two minutes without bringing up the issue of inequality. But when it comes to allowing poor children to escape bad schools and go to better ones he is virtually silent. He opposes public money going to private schools and has little encouraging to say about public school choice. Yet the state he represents (Vermont) has the oldest and most extensive system of school choice found anywhere in the country.

Hillary Clinton’s unwillingness to vigorously stand up for the kids is costing her big campaign contributions. Although she has supported student testing and charter schools in the past, her recent cozying up to the teachers unions is making wealthy school reform Democrats close their checkbooks to her presidential campaign.

To make matters more complex, parents are becoming more of a factor. In a recent election in Los Angeles pro-reform Latino parents managed to prevail against the teachers unions and white voters in affluent suburbs in what USA Today called “the priciest and most bitter school board race in history.”

The Obama administration has been completely inconsistent. Under Education Secretary Arne Duncan, the administration tied state grants and waivers from onerous federal regulations to support for charter schools and the linking of teacher pay to student test scores. His replacement, John King, is a charter school co-founder who, as New York’s education chief, pursued reforms designed to root out bad teachers.

Yet the administration’s Justice Department fought a losing battle in court in an effort to stop Louisiana’s new state-wide voucher program. And the administration joined with Nancy Pelosi and other congressional Democrats in an ongoing struggle to end Washington DC’s Opportunity Scholarship Program. Jeanne Allen of the Center for Education Reform explains the issue this way:

Democrats oppose this program not because it is failing but because it is succeeding. They fear that as these choice programs succeed, poor and minority moms and dads are going to figure out the Democrats are selling their kids out to the teachers unions.

To appreciate what’s at stake, consider two Harlem schools that operate side by side in the same building: Wadleigh Secondary School (a public school) and Harlem West (a charter school). At both schools 95 percent of the students and black and Hispanic and most are from poverty level families. As one of the teachers describes it:

The students … eat in the same cafeteria, exercise in the same gym and enjoy recess in the same courtyard. They also live on the same blocks and face many of the same challenges.

Yet not one of the public school students met state standards in math (a typical question: What is 15% of 60?) or English, while the passing rates at the charter school were 96 and 75 percent, respectively. The city wide scores, by the way, were 35 and 30 percent, despite New York City average spending of $20,331 per pupil.

So, should there be more Harlem Wests and fewer Wadleighs?

Hard to believe, but that is currently the most contentious political issue in New York City and maybe in the whole of New York state.

Also hard to believe, the CNN panel asked not one question about the public schools in last Saturday’s Democratic presidential debate.