WASHINGTON (AP) — Liberal groups are trying to build a grassroots movement that will help revive the economy and protect Medicare and Social Security, but whether they will be successful — and use it to help re-elect President Barack Obama — is unclear.

Organizers of this week's "Take Back the American Dream" conference in Washington have studied the origins of the tea party as they try to build a countermovement to support liberal causes. The effort is a response to Republicans' takeover of the House in 2010 and disenchantment over Obama's attempts at compromise.

After Obama's election, many Democrats said they falsely assumed that winning the White House would help them pass an agenda that would assist middle-class families. Instead, they were dismayed when Obama ditched a proposed "public option" for a government insurance plan from the health care overhaul and cringed when he cut a deal with Republicans to extend Bush-era tax cuts.