I think Rekna has it right on the new ethics law. Thats why Trent Lott resigned from the Senate on Dec. 31.
Many of these Republicans are part of the
Republican Main Street Partnership...the relatively more moderate wing of the Republican party. When the Republicans were in the majority and because of their senority, they had some level of influence as committee chairs......now they are completely marginalized by the party leadership, perhaps leading to their frustration and retirement.
It will be interesting to see if the Republican party will run more conservative candidates for their seats and continue to take the party even more to the right.....as opposed to the Democrats, who in '06, sought out moderate (ie less liberal) candidates.
If that is the case, it can only be a good thing for the Democrats, whose tent is growing while the Republican tent is shrinking.