Stretching what the federal government can do beyond anything that it has previously done.

Jonathan Turley has this in today's USA Today.

Though strong arguments can be made for health care reform and the individual mandate, these are matters that should not be decided by mere fiat of Congress but rather by the courts. Federalism was already on life support before the individual mandate. Make no mistake about it, this plan might provide a bill of good health for the public, but it could amount to a "do not resuscitate" order for federalism.