Martin Luther King Jr. Day is one of the few holidays that really hits me in the gut, that really resonates as a meaningful break from the normal day-to-day routine. It's a day of sober reflection and, sometimes, sadness over an ugly past and an unfulfilled potential. I ritualistically read King's Letter from a Birmingham Jail and watch clips of protesters marching for basic human rights. It's not always a happy day, but it's an important one.

But today is different. It feels different. Tomorrow Barack Hussein Obama will become President of the United States, and like so many others, I never knew when, or if, this day would ever come. The typical somberness and introspection of MLK Day has been replaced with something more optimistic... and a desire to celebrate.

Has King's dream been fulfilled? More than two-thirds of African Americans believe so, according to a CNN poll. That's double the numbers in a similar poll last March. White Americans aren't quite as optimistic: Only 46% say the country has fulfilled King's vision.

I don't know how to answer that question. On the one hand, it's hard to argue that Obama was judged by anything other than the content of his character, and I don't want to discount this milestone and what it says about how far we've come and the possibilities for improving American society. If King were alive today, he would probably have nothing but good things to say.

But Obama's election doesn't mean matters of race are suddenly "solved." And it doesn't mean King's work would have been finished. As I wrote last year, King was about more than a dream for racial equality. He campaigned against wars and for economic justice, and for that he was criticized later in life. It's hard to imagine a man who spoke out against Vietnam and marched for sanitation workers being happy with a war in Iraq and the growing income inequality laid bare by the current economic crisis.

Still, even if the dream isn't fulfilled, there's more of a sense than ever that it can be. Parents from all races and ethnicities can tell their children that they can grow up to be anything their heart desires, and mean it. From here on out, children won't see a never-ending string of old white men when they study U.S. presidents in school. People who have grown more and more cynical at the indifference of the Bush administration can feel represented again.

It boils down to hope. King's greatest contribution to American society wasn't an immediate solution to racial inequality; it was a dream—a hope—that it could happen. That's what he and Obama have in common, and it's why this MLK day feels so different from others in recent years. We may still have a lot of problems to solve, but much of the country seems to have regained its sense that our better days are yet ahead. Starting tomorrow around noon.