Obama Flashback - Obama promised to 'walk on that picket line'

In a November 3, 2007 speech in Spartanburg, South Carolina, presidential candidate Barack Obama promised to walk the "picket line":

"And 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 will walk on that picket line with you as President of the United States of America. Because workers deserve to know that somebody is standing in their corner."

Watch the video:

So why isn't Obama in Madison instead of tyring to back away from the demonstrations he and his campaign organizations supported?