Charlie Cook makes a good point:
The one sobering thought that veteran Republican consultants are already contemplating is that the larger the wave this year, the more difficult it will be to hold onto some of these seats in 2012 and 2014 in the House and 2016 in the Senate.
The bigger the wave, the weaker the class and the harder it will be to hold onto those seats. Democrats only have to look at their 2006 and 2008 classes for plenty of examples.
What this means is that we will likely have our third wave election in a row this year, and the bigger this one is, the more likely that there will be a countervailing wave in either 2012 or 2014.
Keep this in mind when Republicans are claiming a mandate come Nov. 3. Given the size of the Democratic majority, it was really only a matter of time before Republicans won another majority in Congress. The truth is that voters are mostly responding to economic conditions, and as those conditions change, so will their votes. My guess is that 2014 -- or even 2012 -- will see large Democratic gains, as voters swing to favoring the minority party for reasons that have nothing to do with ideology and everything to do with the combination of economic conditions, weak incumbents, and the fickle reasoning of the median voter.
-- Jamelle Bouie