Building on John Isaacs' excellent analysis, I would add these three points:

1. In the House and Senate there is a three party system: liberal Democrats, moderate Democrats and on most matters a Republican Party that stands for negativity and a veto all initiatives that are not Republican.
   
2. Republicans should be expected to say where they stand on extremism. Even self professed moderates e.g. Governor Pataki succumbed to supporting the extreme candidate in the NY race.
   

Right now Republican officeholders and candidates are decidedly "soft on extremism." Thatis a fair label of attack by anti-extremists.
3. Democrats have a big "get out the vote" problem.
If it is not corrected, the 2010 elections will be worse than the usual off year elections are to  the party in power. It could resemble 1994.
In the NY House race the Republicans hurt themselves with ideological purity. Majorities require keeping moderate and liberal Democrats tracking together in the House and Senate.
Our challenge on getting the Senate to "advise and consent" is to keep a solid Democratic phalanx and cut through Republican negativity and destruction to
get to 67 on the essential treaties including CTBT.
David Cohen