Charlie Cook looks beyond 2010:
The bigger the wave [this year], 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.
(Photo: David McNew/Getty.)