|Is this also some type of "mandate?"|
Congress has repeatedly used broad interpretations of the Constitution to insert itself into the conduct of commerce, so the mandate is nothing new. One past example is the prohibition against gender, religious or racial discrimination by private firms, while another is the ban on home grown medicinal marijuana. Since health care is a commercial activity in the public space, the logic is that Congress can similarly require anyone who has ever received health care in the past to purchase health insurance for the future.
While prohibiting an activity (like discrimination or pot) may not be the same as requiring an activity (health insurance), readers may be interested in knowing that the first Congress not only required ship owners to buy medical insurance for merchant seamen but later required seamen to buy hospital insurance.
And what about that mortgage deduction? If you don't buy a house, you can't take the deduction, which economically the same as a penalty for not engaging in the economic activity of home ownership.
Another favorite of mandate opponents is the argument that the Feds are on a slippery slope leading to a requirement that we all buy broccoli or General Motors cars. The counter argument is that Medicare is a system that requires the purchase of "broccoli" at government stores. What's more, if we were to privatize Medicare, wouldn't that also functionally be a mandate for the purchase of private insurance?
Last but not least, if personal liberty is the underlying issue, the argument is that no one would ever force anyone to eat the broccoli. Mandating insurance is not the same as mandating health care.