Barack Obama in Spartanburg, S.C. on November 3, 2007
"Understand this. If American workers are being denied their right to organize and collectively bargain, when I'm in the White House, I'll put on a comfortable pair of shoes myself. I'll walk on that picket line with you as President of the United States because Americans deserve to know that somebody is standing in their corner."
Barack Obama to the Congressional Black Caucus on September 24, 2011
"I expect all of you to march with me and press on. Take off your bedroom slippers, put on your marching shoes. Shake it off. Stop complaining, stop grumbling, stop crying."
Try Robert Johnson: http://www.youtube.com/watch?v=MEsQikthT3Q&feature=related.