Barack Obama:
“One of the things that I’ve felt very strongly about during the course of this year is that hard stuff requires not paralysis, but it requires going ahead and trying to make the best of the situation that you’re in.”
Doesn't have quite the same ring as "the fierce urgency of now," does it? And in fact, MLK's next line was this:
"This is no time to engage in the luxury of cooling off or to take the tranquilizing drug of gradualism."
Of course, Martin Luther King never met Ben Nelson.