But not as low as Congressional Republicans

Let's face it.  There isn't an entity in America, short of cockroaches and listeria, that's less popular than Congressional Republicans.  Get up into the C+ to D- range, and there's greater diversity among the unpopular people.  The Red Sox, broccoli, and clamshell packaging group of unpopular things.  That's where the tea party and Obama find themselves, though the tea party is moving downward towards cockroaches and Obama is moving up towards decent coffee that's not hot enough.

For the first time, a majority of Americans--53 percent--have an unfavorable view of the Tea Party, just slightly edging past the president's disapproval of 52 percent, according to a recent CNN poll. Disapproval of the barely two-year-old right-wing political movement has finally caught up to Obama's. ...Atlantic