Only Obama's speech was about putting King's principles into action.

An excerpt from his Fort Wayne speech:

In the dark days after Dr. King's death, Coretta Scott King pointed out the stars. She took up her husband's cause and led a march in Memphis. But while those sanitation workers eventually got their union contract, the struggle for economic justice remains an unfinished part of the King legacy. Because the dream is still out of reach for too many Americans. Just this morning, it was announced that more Americans are unemployed now than at any time in years. And all across this country, families are facing rising costs, stagnant wages, and the terrible burden of losing a home.

Part of the problem is that for a long time, we've had a politics that's been too small for the scale of the challenges we face. This is something I spoke about a few weeks ago in a speech I gave in Philadelphia. And what I said was that instead of having a politics that lives up to Dr. King's call for unity, we've had a politics that's used race to drive us apart, when all this does is feed the forces of division and distraction, and stop us from solving our problems.

That is why the great need of this hour is much the same as it was when Dr. King delivered his sermon in Memphis. We have to recognize that while we each have a different past, we all share the same hopes for the future - that we'll be able to find a job that pays a decent wage, that there will be affordable health care when we get sick, that we'll be able to send our kids to college, and that after a lifetime of hard work, we'll be able to retire with security. They're common hopes, modest dreams.  And they're at the heart of the struggle for freedom, dignity, and humanity that Dr. King began, and that it is our task to complete.

You know, Dr. King once said that the arc of the moral universe is long, but that it bends toward justice. But what he also knew was that it doesn't bend on its own. It bends because each of us puts our hands on that arc and bends it in the direction of justice.

So on this day - of all days - let's each do our part to bend that arc.

Let's bend that arc toward justice.

Let's bend that arc toward opportunity.

Let's bend that arc toward prosperity for all.

And if we can do that and march together - as one nation, and one people - then we won't just be keeping faith with what Dr. King lived and died for, we'll be making real the words of Amos that he invoked so often, and "let justice roll down like water and righteousness like a mighty stream."