Not to be too defensive but part of the reason is the way our side thinks. Republicans are individuals while Democrats are in group-think mode. We tend to stand or fall based on our own merits, while they do better propping themselves up because they realize that when one falls it affects the entire group.
Republicans may blame an individual for something but we rarely blame the other party. Democrats will blame the whole party for the actions of one individual.
Just a newspaper media report...
The Fort Worth Star-Telegrams front page headline, above the fold is:
"1,951-mile fence proposed to seal U.S.-Mexico border"...
First quote in article is from Duncan Hunter saying the fence is necessary.
You don't sound defensive....you are just pointing out differences between party members...and I agree with it.
However, the perception is that the party isn't together, and is turning against President Bush..
Unfortunately, in the world we live in, in some cases, "image is everything"...and that image/perception is contoured by the MSM...so, the Republicans get lumped together, and dumped on together.