Megan McArdle has identified 11 and most of them I agree with. Here is number 3:
Myth: ObamaCare works because it gets money from deadbeats who go to the emergency room and then stiff the rest of us for the cost. Actually, hospitals have a pretty effective mechanism for collecting money from the deadbeats: debt collectors. Uncompensated care is definitely a problem, and it will almost certainly fall under Obamacare. But in Massachusetts, which achieved much higher coverage rates than most states will see (90 percent of the state was insured when they started, and they have comparatively few illegal immigrants), such care fell by less than half between 2006 and 2010…
Moreover, this is a relatively small amount of overall health spending — about $62 billion in 2009, on total health spending in the trillions. Obamacare mostly works by getting young and healthy people to spend more on health care than they otherwise would, thus subsidizing older and sicker people. You can argue that this is unfair, or that it’s merely a down-payment on their own future as old and sick people. But either way, this is the real mechanism for making the insurance expansion affordable to individuals, and the government.