The republican party is eating itself

While I'm stating the obvious am I the last person to find out Brett Favre is now a Viking?
:P
Seriously though, I wonder if its a good thing--forcing ideological purity upon party members. I mean right now the democrats, having not done that the last two election cycles, are having some troubles with so called "blue dogs" who are trying to strip healthcare reform of its teeth in the name of moderation and keeping their seat in districts that leaned McCain in '08.
So, from the perspective of effectiveness is it better to loose seats in congress, but have lock-step control over those congress-people you do have, or to have a lot more folk of your party in congress but have intra-party squabbles?