The so-called blue dogs are a media invention designed to make the Democrat party appear something other than a monolithic liberal political machine.
UPDATE:
Heh. Buy the t-shirt.
UPDATE II:
More on the fearsome blue dogs here.
UPDATE III:
Good observation from John McCain. Incidentally, much as there is to dislike about the guy, do you ever find yourself saying “my what a better president he would have been?”

So, put all the illegal aliens in the government option plan. Good luck to them.
Yeah, if I was a betting man that’s what I would bet is going to happen. Bad news for anyone over 65 who is not rich.
Saving money by having sick illegal aliens walking the streets. Terrific solution!
Joe
You nailed it. The SO CALLED Blue dogs are lap dogs in disquise. There may be a handful of these Democrats who reject the Pelosi memo, however, the rest of them are creations of Dead Fish Rahm. Created to blow smoke up the rear end of what used to be called Reagan Democrats. They are however simply a group one half click right of the hard lefties who have taken over the Democrat party being led by Hopey Changey himself.
If anyone believes the Blue Dogs to be a real force in the Democrat party, I have some ocean front property in Berkley West Virginia I would like to sell you.
Keep trying to sell that property in the Springs, Stoner. If they listen long enough to Al Gore on global warming, there may be some liberals out there ready to believe that the ocean front could eventually be just about on a line with Route 522. You might even consider calling the property “Stoner’s Cove” and putting up a combined real estate office and fish and clam joint in one of those old buildings right across the road from the high school. On Thursdays, you could serve a cut-rate “Blue Dogfish Special” for Democrat early birds — so long as they can show you a copy of their original birth certificate.