In a piece by Dana Milbank about how Nancy Pelosi has become irrelevant, and by doing so, Obama has become "rudderless", there's this:

On the eve of Obama's speech Wednesday outlining his budget goals, liberal groups such as MoveOn.org and Campaign for America's Future began to mobilize in anticipation that he would again acquiesce to Republican positions. Privately, Pelosi used that opening to reassert her influence with the president.

She called up White House Chief of Staff Bill Daley and drew a line in the sand: Democrats couldn't tolerate capitulation by Obama to Republican demands for a restructuring of Medicare, which they hope to make the central campaign issue of 2012.

"Let me be absolutely clear," Obama said Wednesday. "I will not allow Medicare to become a voucher program that leaves seniors at the mercy of the insurance industry." The partisan speech infuriated Republicans, set back negotiations in the Senate - and delighted Democratic activists.

But the next morning, Obama was in the Oval Office with the chairmen of his bipartisan debt commission, whose recommendations have inflamed liberals. "Very frankly, it is the framework that they developed that helps to shape my thinking," he said.