In 2008, the Council of Great City Schools examined the Milwaukee Public Schools and found us wanting. We had the highest suspension rate of any urban district in the country; we issued more days of out-of-school suspension than the Los Angeles Unified School District, which enrolls seven times as many students.

And we suspended African American students at a rate more than double the rate of white students.

Those numbers were indefensible. I don't think anyone stood up back then and said that sounded right. The numbers also weren't completely unique to MPS; districts all over the country over-suspended, and significantly over-suspended black students.

Today, MPS's suspension rate is down dramatically. (It is nationally, too.) The number of students suspended by MPS in 2012-13, the most recent year with data available from the state, was half what it was in 2007-08. Because of a drop in overall enrollment, the percentage drop is less than half – from 30.3 percent to 17.4 percent – but any way you slice it, the turnaround is huge.

Fewer African American students are being suspended, too, down from 41.5 percent of black students in 2007-08 to 26.1 percent in 2012-13.

Yet the racial disparity remains: in 2012-13, only 7 percent of white students were suspended. We're still suspending black students at least three times more often than white ones. Indeed, a report out earlier this year from the Civil Rights Project at UCLA said that, based on slightly older data (from 2010-11 and 2011-12), Wisconsin had the highest suspension rate in the country for African American high school students.

Is it because white teachers (like me) are racist? I have been asked this before, casually in conversation with friends or acquaintances and seriously by people trying to get to the root of the problem – even by a fellow OnMilwaukee columnist worried that MPS teachers might be setting their expectations too low.

I tend to answer no. I don't know every white teacher in the district, of course. But in my experience, you don't go into this job in this district if you don't like black kids. I cannot think of a colleague who holds that kind of prejudice, and the African American teachers I know tend to complain about the same kinds of classroom challenges that I see.

I do try to keep in mind, though, that racism is not, to paraphrase Peggy McIntosh's classic writing about white privilege, simply individual acts of racial disparity committed by prejudiced people with cruel intentions. It is also an entire cultural and socioeconomic system that confers advantage and privilege to some and disadvantage and challenge to others.

So I also tend to answer that there may well be something happening systemically, in or out of school, that encourages African American students to engage in inappropriate behavior more often than their white counterparts.

The spring issue of the conservative Wisconsin Policy Research Institute's journal Public Interest considered the question of suspensions in Milwaukee, Racine and Madison, and asked the question about racist teachers, too.

The story cites academics who study the issue, saying that there may be "a subconscious bias by teachers that stereotypes black males as 'dangerous,'" with them "falling victim to implicit prejudices without the teacher even realizing what is happening."

When I read that last month, I wasn't sure how to feel about it. The story offers some other views, including a scene of an African American activist from Madison having difficulty with behavior in a classroom he visited, that were more along the lines of my usual answer to the question.

And overall, the story's suggestion that such a steep drop in suspensions is creating new challenges in classroom management rings true to me. I certainly hear over and over that students just don't get suspended any more, and they know it, so they feel emboldened to keep acting out. But that "are teachers just racist?" question hung on.

A new study out this month is further challenging my stance. Researchers at Stanford used an interesting methodology to try to measure subconscious or implicit racial bias teachers. They found that teachers seeing a single discipline referral for students with a stereotypically black name (like DeShawn) didn't react differently from teachers seeing a referral for a student with a white name (like Jake).

But when teachers saw a second referral for those students, they reacted more strongly to the students perceived to be African American, rating the severity of identical infractions higher for the black students, and being more likely to say that it represented a pattern of troubling behavior for them.

I shouldn't really be surprised by this. I mean, I've long wondered whether some similar implicit racial bias might be, at some level, responsible for things like police shootings of unarmed black men and teenagers, for example.

The question is, if this is true, what can we do to overcome it? Writing about, not coincidentally, police shootings, science writer Chris Mooney reports for Mother Jones that there are ways to move people away from their implicit biases.

"The single best intervention involved putting people into scenarios and mindsets in which a black person became their ally," Mooney writes. "In other words, study subjects are induced to feel as if they have been personally helped or even saved by someone from a different race." It's kind of like the conservative politicians who come out for gay marriage only after they learn of a gay relative.

The problem, of course, is that there's no good way to have all of us white folk get saved from certain death by, say, Power Man Luke Cage. But it might help if places like Milwaukee were less segregated, making it more likely that your average teacher (or police officer, or loan officer for that matter) is neighbors and friends with people of many races.

Mooney does say that one good, non-comic book first step that doesn't involve desegregation is making sure people are aware of their implicit prejudice. Not simply making people aware that there are implicit biases in the system generally, but that they themselves hold biases. There are programs like this for police, Mooney says, such as the Fair and Impartial Policing program supported by the U.S. Department of Justice.

But I know of no similar program for teachers; in all the years of in-service I've sat through, including many about how to teach with racial and cultural sensitivity, I've not seen one designed to show teachers their own implicit bias. There's probably a dissertation in that for someone somewhere, or at least a good action research project for one of my teacher friends. Let's get on this, Milwaukee.

Of course, I don't think this is what my trolls – they know who they are – mean when they try to tell me that I'm the real racist. Still, I hope that they sleep a little better tonight knowing that they may just be right for once.