Obama has often been called upon to use his unique historical position as the first black president to engage the nation in a conversation about continuing racial injustice. In a surprise appearance in the White House briefing room just now, he waded into the debate over the shooting of Trayvon Martin in a remarkably personal manner that will probably cause far more extensive ripples than even his big 2008 race speech did.

Obama’s remarks will be chewed over for some time to come, but I just wanted to focus for now on a couple aspects of it. Obama made what amounted to an extended plea for people to try to understand how African Americans might view the shooting of Trayvon. He then segued into a discussion of “stand your ground” laws:

I know that there’s been commentary about the fact that the stand your ground laws in Florida were not used as a defense in the case.

On the other hand, if we’re sending a message as a society in our communities that someone who is armed potentially has the right to use those firearms even if there’s a way for them to exit from a situation, is that really going to be contributing to the kind of peace and security and order that we’d like to see?

And for those who resist that idea that we should think about something like these “stand your ground” laws, I just ask people to consider if Trayvon Martin was of age and armed, could he have stood his ground on that sidewalk? And do we actually think that he would have been justified in shooting Mr. Zimmerman, who had followed him in a car, because he felt threatened?

And if the answer to that question is at least ambiguous, it seems to me that we might want to examine those kinds of laws.

Obama is stating that the evaluation of such laws cannot be divorced from a racial context. In his initial response to the verdict, Obama avoided the topic of race, and alluded only to the “passions” that it had unleashed, in essence striking the tone of conciliation that has become so familiar. Today Obama placed the debate over the shooting — and over stand your ground laws — squarely in the context of the African American experience and the country’s history of racial discrimination, arguing, in effect, that race is inevitably the subtext of such arguments.

Indeed, Obama used his own experience to drive home that point. In the part that will probably get the most attention, he discussed his own experience of being followed in department stores and hearing car doors get locked when he walked past. But to me his personal comments were most interesting at the end, when he brought his children into it:

As difficult and challenging as this whole episode has been for a lot of people, I don’t want us to lose sight that things are getting better. Each successive generation seems to be making progress in changing attitudes when it comes to race. It doesn’t mean that we’re in a post-racial society. It doesn’t mean that racism is eliminated. But you know, when I talk to Malia and Sasha and I listen to their friends and I see them interact, they’re better than we are. They’re better than we were on these issues. And that’s true in every community that I’ve visited all across the country.

And so, you know, we have to be vigilant and we have to work on these issues, and those of us in authority should be doing everything we can to encourage the better angels of our nature as opposed to using these episodes to heighten divisions. But we should also have confidence that kids these days I think have more sense than we did back then, and certainly more than our parents did or our grandparents did, and that along this long, difficult journey, you know, we’re becoming a more perfect union — not a perfect union, but a more perfect union.

It should be noted that Obama downplayed expectations for any kind of federal prosecution of George Zimmerman. “It’s important for people to have some clear expectations here,” he said. “Traditionally, these are issues of state and local government — the criminal code.” In other words, this likely won’t end in the way many Martin supporters hoped.

And so, after delivering what was at bottom a very pessimistic message — racial discrimination is very much still with us, and any conversation politicians have is unlikely to do all that much to fix things — Obama sought to end on a more optimistic and conciliatory note. To use the formulation he often employs, he was saying the arc of history is bending in the right direction.

All of us who have kids, I imagine, look at them and marvel at how much smarter and more sensible they seem than we are. It’s a way of telling ourselves that the world they grow up in will be better than our own. Given the country’s awful history of racial discrimination, it was particularly interesting and dramatic to see the nation’s first black president –  himself perhaps the best known symbol of racial progress on the planet — look to his own children, and their interaction with their peers, as a source of hope that the world continues to become, however slowly, a better place.

Greg Sargent writes The Plum Line blog, a reported opinion blog with a liberal slant -- what you might call “opinionated reporting” from the left.