Ralph Nader and Cornel West, among others, are banding together to put forward a primary challenge to Obama:

Mr. Nader said the intent is not to defeat Mr. Obama but to make him focus on issues that might get lost in a purely Obama-versus-GOP discussion. Defeating an incumbent in a primary is a tall order, but opponents can expose weaknesses, as Patrick J. Buchanan did in 1992 to the first President Bush and Sen. Edward M. Kennedy did in 1980 to President Carter. 

In its recruitment letter, the group faulted the administration's handling of the Wall Street bailouts, the wars in Afghanistan and Pakistan, and the U.S. involvement in the military effort in Libya. They also criticized Mr. Obama's decision to extend the Bush-era tax cuts and the recent deal he struck with Republicans over cutting spending to raise the debt ceiling. 

"We need to put strong Democratic pressure on President Obama in the name of poor and working people" said Cornel West, an author and professor at Princeton University. "His administration has tilted too much toward Wall Street, we need policies that empower Main Street."