Is it time for an organized "Party Within the Party"?

After the GOP got their butts handed to them in 2006 and 2008, Dick Armey, one of the "Contract With America" architects from the 90s, and others formed the Tea Party. While the movement started principally as a protest against taxation and spending, it has since taken on a life of it's own. It now serves as an organized "party within a party." Especially at primary time, the Tea Party has served as an organization that forces Republican politicians to move further and further away from the political center to an orthodox, ultra conservative agenda that formerly existed only in the wildest fantasies of Rush Limbaugh and Roger Ailes.

In the 80s and early 90s, the Democrats had an organization that was designed to perform the precisely opposite task. The DLC (Democratic Leadership Council) was led by Al From, and billed its members as the "New Democrats." Their mission was to bring the party closer to the center. They are credited (rightly or wrongly) with helping to get Bill Clinton elected.

Is it time for leaders like Alan Grayson, and organizers from groups such as "Occupy" and "Code Pink" to lead and organize a movement analogous to the Tea Party to move the agenda of the Democratic party further to the left. Is it time to attempt to replace centrist Democrats with candidates who are more stridently anti-war, anti-poverty, and pro-environment? Or, is the lesson of the Tea Party that moving to far away from the political center leads to a legislature that can't compromise enough to get anything accomplished, and that will alienate mainstream voters in the long run?