Here's proof that the 112th Congress was the most polarized ever

The Washington Post highlights the latst research from Voteview showing that ideological polarization between party members in Congress contines to increase, and is now at its highest levels ever, and that most of the ideological shift has been among congressional Republicans.



For additional detail click on either link above. Here's explanation from the WP:

The Democratic caucus got more liberal this past Congress as a lot of Blue Dogs and conservative Southern Dems lost their seats in the 2010 elections, and in general the party has been getting gradually more liberal since the 1930s. And from the ’30s to the ’70s, the Republican caucus was slowly getting more liberal too. But around 1976, it suddenly shifted and grew rapidly more conservative, and has continued to do so ever since. The Tea Party movement doesn’t appear to have sped that process up much, but then again many of its successes came in primaries to determine challengers for Democratic seats, in which those challengers (like Sharron Angle or Christine O’Donnell) went on to lose. That wouldn’t show up in these figures.