Those who have never despaired have neither lived nor loved. Hope is inseparable from despair. Those of us who truly hope make despair a constant companion whom we out-wrestle every day owing to our commitment to justice, love, and hope.
I think it's important not to view Martin Luther King Jr. in a narrow political manner. His fundamental commitment is to a radical love of humanity, and especially of poor and working people. And that radical love leads him to a radical analysis of power, domination and oppression. What's difficult is to situate him ideologically under a particular category.