Poll: Only 6% of Voters Think Congress Deserves Re-election

Another new low for the Democrats and Republicans, this time in a CBS News poll:

Just 12 percent of Americans approve of the job Congress is doing - the same as the lowest percentage recorded in this poll, reached in October 2008, right before the November elections. Dissatisfaction with Congress cuts across party lines. Republicans, Democrats, and independents all overwhelmingly disapprove of the job Congress is doing. . . .

In keeping with Congress' dismal review, just 6 percent of registered voters think most members deserve re-election - the lowest percentage ever in CBS News Polls during the past 20 years, and a lower percentage than the 9 percent who thought so right before the 2010 midterms. . . .

Americans are usually more positive when assessing their own representative in Congress.
That's true now, too - 33 percent say their representative deserves re election - but nearly six in 10 registered voters don't think their own representative deserves re-election. 

Americans consistently say that they want to "throw all the bums out," but then come election day, they almost invariably vote to keep them in office.  How can we explain this contradiction?