One could ask why isn’t the individual income tax held to the same standard either.
The biggest difference is that the FICA and Medicare taxes are charged to you based upon you earning income (13th Amendment says OK).
The individual mandate is worded as a “penalty”
In Section 1501 of Public Law 111-148, it says,
(1) IN GENERAL- If an applicable individual fails to meet the requirement of subsection (a) for 1 or more months during any calendar year beginning after 2013, then, except as provided in subsection (d), there is hereby imposed a penalty with respect to the individual in the amount determined under subsection ©
So therefore, the government is mandating that you, as an individual, engage in commerce or face a penalty (that is unconstitutional according to this judge). In addition, that is essentially a fine, but you aren’t convicted of a crime (which would be a violation of 5th Amendment rights…but that part hadn’t come up yet).
(It could be worded so that it was constitutional, though. All they’d have to do is to make a tax on everybody and then give everybody who has acceptable insurance a tax credit that is exactly the same as that tax. Darn the bad luck, those evil Republicans control the House as of Jan 3rd…so that change won’t ever happen…darn…shucks…hee…hee…)
(Nothing above should be interpreted as saying that I support either social security old age retirement, medicare old age insurance, or Obamacare)