Sorry Republicans, it appears to be due to the world's largest government medical research program. The American National Institutes of Health spends $28 billion on medical research, dwarfing every other program on the planet. Read more at Jonathan Cohn's excellent article.
With universal health care, under the proper plan we could cover everyone and even expand this research at much less money then we spend now. First good story out of TNR in years?
In other healthcare news the Mass. universal plan is working.