The rejection of the Commerce Clause and Nec. and Proper Clause should be understood as a major blow to Congress's authority to pass social welfare laws. Using the tax code -- especially in the current political environment -- to promote social welfare is going to be a very chancy proposition.
and Scotusblog also points out the incongruity of it NOT being a tax for purposes of the AntiInjunction Act [considering is such for AIA would have meant they did not have jurisdiction to consider it bc there would be no harm as no tax has yet been collected] but it IS a tax for purposes of upholding constitutionality.