Why would these "Blue Dogs" bark for health care reform?

Why would the so-called "Blue Dog" Democrats support health care reform? I found that a large majority of the so-called "Blue Dogs" aren't in the pockets of the Insurance industry, but a fair amount of them actually have taken large amounts from the industry. Three members stand out in the crowd. Dennis Moore of KS, has taken $49,000 from the insurance industry for '09-'10. Running a near second is John Tanner, TN. He took $47,800. Charles Wilson took a paltry $24,750. All through the list of "Blue Dogs" I saw contributions from Health Professionals. That adds up to a lot of kibble coming from the healthcare industry. The "Blue Dog" most popular in that department is Earl Pomeroy of North Dakota. His take amounts to $98,885. I won't call them all out because I can't really figure out where "Health Professionals" plays out in the big game of campaign contributions. But quite a few had HUGE contributions. But I did want to find out who in the Democrat party had their hands in the Insurance industry pot. The Democrats were not famous in the past for being bought and sold, What is going on today?