I would argue that you already have Rachel Maddow, Keith Olbermann, and the liberal Netroots leading a movement. The problem is that such a movement can only have limited effectiveness when it is undercut by our own political leaders. From Harold Meyerson in the Washington Post:
In America, major liberal reforms require not just liberal governments, but autonomous, vibrant mass movements, usually led by activists who stand at or beyond liberalism's left fringe. No such movements were around during Carter and Clinton's presidencies. For his part, Obama won election with something new under the political sun: a list of 13 million people who had supported his campaign. But he has consistently declined to activate his activists to help him win legislative battles by pressuring, for instance, those Democratic members of Congress who have weakened or blocked his major bills. To be sure, loosing the activists would have brought problems of its own: Unlike Roosevelt or Johnson, who benefited from autonomous movements, Obama would be answerable for every loopy tactic his followers employed. But in the absence of both a free-standing movement and a legion of loyalists, Congress isn't feeling much pressure from the left to move Obama's agenda.
The construction of social movements is always a bit of a mystery. The right has had great success over the past year in building a movement that isn't really for anything but that has channeled anew the fears and loathings of millions of Americans. If Glenn Beck can help do that for the right, can't, say, Rachel Maddow and Keith Olbermann help build a movement against the banks or for jobs programs? It might well be too little too late, but without left pressure from below, the Obama presidency will end up looking more like Carter's or Clinton's than Roosevelt's or Johnson's.
