Health insurers make enormous amounts of money off of us, something they cannot do so effectively in other countries, especially Canada. The four largest insurers, United, WellPoint, Aetna and CIGNA, reported earning a combined $11 billion on nearly $220 billion in revenues last year. For years insurers have been successful in persuading Americans to believe something that is at best debatable -- that they play a useful role in the U.S. health care system. They are nervous that if Vermont proves to the rest of the country that health insurers are about as useful as teats on a boar, they might have to figure out another way to make a few billion bucks.