Republicans debated in a city with a horrible police shooting. It got no attention.

The Republican debate in North Charleston, South Carolina, was supposed to be the one where the presidential candidates finally talked about the racial disparities in police shootings. Last April, a North Charleston police officer shot a fleeing black man, Walter Scott, multiple times in the back. It was such an abhorrent shooting that Fox News host Sean Hannity, a conservative defender of police, called it unjustified. Michael Slager, the cop who fired at least eight shots at the fleeing man, is on trial right now for murder charges.

Yet the shooting and issues surrounding it never really came up during the debate, just like they haven’t come up in all the previous debates aside from some brief mentions here and there.

This is a serious national topic. It may not be particularly popular in Republican circles, but concern over racial bias and police brutality have led to massive protests — and riots, a show of real anger within some communities — in major cities. It was one of the biggest topics on Twitter two years in a row. Polls also show the public is now more likely, compared with the past one to three decades, to say racism is a big problem and police treat black people unfairly, and less likely to say they have quite a lot or a great deal of confidence in the police.

It’s also a problem that is backed by the data. An analysis of the available FBI data by Vox’s Dara Lind found that US police kill black people at disproportionate rates: Black people accounted for 31 percent of known police killing victims in 2012, even though they made up just 13 percent of the US population. Although the data is incomplete because it’s based on voluntary reports from police agencies around the country, it highlights the vast disparities in how police use force.

And it’s an issue that may genuinely split the Republican field, making for a great debate back and forth.

Many conservative defenders of police look at the data above and argue, for example, that it’s a representation not of police wrongdoing but of systemic problems in minority communities, where crime and poverty are higher. (The research, to be clear, doesn’t fully support this view: It suggests that subconscious racial biases exist among police officers, and higher crime rates in black communities only explained about 61 to 80 percent of black overrepresentation in, for example, prisons.)

But Marco Rubio, who’s commonly touted as the Republican establishment’s best shot, has a divergent view. Last year, he said on Fox News:

This is a legitimate issue. It is a fact that in the African-American community around this country there has been, for a number of years now, a growing resentment toward the way law enforcement and the criminal justice system interacts with the community. It is particularly endemic among young African-American males — that in some communities in this country have a much higher chance of interacting with criminal justice than higher education. We do need to face this. It is a serious problem in this country. …

I have one friend in particular who’s been stopped in the last 18 months eight to nine different times. Never got a ticket for being stopped — just stopped. If that happened to me, after eight or nine times, I’d be wondering what’s going on here. I’d be upset about it. So would anybody else.

But where do other candidates stand on this issue? It’s unclear. They’ve given vague talk about supporting police officers. But practically everyone supports police officers; the issue is, instead, whether you think police need to be trained better or differently, or department guidelines need to change, or maybe even the law governing police use of force needs to change.

Yet debate audiences never hear significant talk about this issue, even as question after question is asked about whether Ted Cruz is a natural-born citizen or whether Donald Trump is too mean to run for president.

These debates are supposed to be the American public’s chance to hear about genuine differences between the candidates. This issue is very big, and it could expose some of those differences. Yet debate after debate, it goes ignored.