ACA fallout

I wonder what percent of those who oppose the ACA and specifically the individual mandate can explain why it is unconstitutional?  Under our Supreme Court's current interpretation of the Constitution what precedent does this law violate?  Likewise I wonder what percent of those in favor of ACA and the individual mandate can explain why it is constitutional.  Obviously our legal system doesn't place equal burden on both sides of the argument.  A law is a priori assumed to be constitutional unless and until the courts say it is not.   (Pre-clearence by some states of voter laws is the one possible exception that I know of).

Furthermore, I would bet that 99+ percent of those who hold an opinion on the constitutionality of the ACA aligned themselves on the issue entirely independent of the constitutionality issue.  Rather they picked a side and that drove whether they felt the law was constitutional.  How many people (other than a few law professors) care whether the ACA is constitutional under the Commerce Clause or under the Federal governments right to tax authority?   Mitt Romney obviously didn't have a problem with the constitutionality of the individual mandate back in 2007  when he imposed it in Massachusetts.  Yeah that was a cheap shot...but I had to get it in somewhere.

Before I leave this topic - this one and this one are kind of funny as well.