In a long-ago high school civics class, I was told that our legal system is predicated on the idea that it is so important to prevent harm to one innocent person that we would rather see some of the guilty go free than punish those who have done no wrong.

Let's admit that's just a lie.

A study out today shows that we have exonerated more than 2,000 people in the last two decades who were initially convicted. More than half of those exonerated were African American.

That news comes in the wake of nearly irrefutable evidence that Texas executed an innocent man, Carlos DeLuna, in 1989 and that a Texas judge that reviewed the 2004 execution of Cameron Todd Willingham was about to issue him a posthumous exoneration before the review was stopped by an appeals court.

And let us not forget the news that House Republicans are so concerned that a couple of ineligible immigrant women might seek permanent residency visas under the Violence Against Women Act's provisions for immigrant victims of domestic violence or sexual violence that they're seeking to kill protections for all immigrant victims to domestic and sexual violence in order to keep the mythical abusers of the system from gaming it.

And then there's New York City's stop-and-frisk policy under which 80 percent of the 2.8 million people stopped between 2004 and 2009 were African-American or Latino, and 90 percent had committed no crime.

The reality is that we regularly incarcerate people who are certainly innocent because the system is shoddy, the people making the decisions in it are as flawed as the rest of us, it's easily gamed with the copious application of money and, at the end of the day, no one in any position of power is particularly interested in overhauling it -- or being responsible for the one guilty person that gets off to make sure that one innocent person never sees the inside of a jail cell.

["Young Man Handcuffed" on Shutterstock]