Wickard v. Filburn, 1942.
Wickard v. Filburn, 317 U.S. 111 (1942), was a U.S. Supreme Court decision that dramatically increased the power of the federal government to regulate economic activity. A farmer, Roscoe Filburn, was growing wheat to feed his chickens. The U.S. government had imposed limits on wheat production based on acreage owned by a farmer, in order to drive up wheat prices during the Great Depression, and Filburn was growing more than the limits permitted. Filburn was ordered to destroy his crops and pay a fine.
The Supreme Court, interpreting the United States Constitution's Commerce Clause (which permits the United States Congress to "regulate Commerce . . . among the several States") decided that, because Filburn's wheat growing activities reduced the amount of wheat he would buy for chicken feed on the open market, and because wheat was traded nationally, Filburn's production of more wheat than he was allotted was affecting interstate commerce, and so could be regulated by the federal government.
Wickard v. Filburn today provides the legal underpinnings for literally THOUSANDS of laws, and is actively cited in cases regularly. It also provides the legal foundation on which many of our federal civil rights laws are based, is regularly cited when new environmental laws are drafted, and overturning it would be a Libertarians dream as it would strip the federal government of vast portions of its authority. Before Wickard v. Filburn, there was NO legal basis for Congress to pass ANY laws that didn't impact commerce between states. Most laws governing business were written at the state level, and we all know how well THAT worked.
So, here's why it's constitutional: By not purchasing health insurance, you are impacting the price of health insurance in this country, which is a product that is subject to the interstate commerce clause. Because your lack of purchasing is negatively impacting an economic activity that Congress DOES have an ability to regulate, Wickard v. Filburn grants Congress the right to regulate your decision. By not buying wheat, Filburn negatively impacted the wheat market. By not buying insurance, many Americans are negatively impacting the insurance market. The USSC granted Congress the ability to require Mr. Filburn to buy wheat, and the ability to require you and I to buy insurance.
I don't like this health care bill, and I hope it goes down in flames, but anyone hoping for a hail mary pass from the USSC is going to be sorely disappointed.