I find this whole discussion incredibly interesting.
Although I oppose the taxation of non child bearing people, with the political structure we currently have, the arguments for such a tax make incredible sense. You simply can't just go down this taxation road once, then tell a group that wields incredible power, the child providers, they aren't allowed down that road.
See, to me this gets at the
real meaning of the "General Welfare" clause, before it got lawyered into an excuse for expanding state power.
The general welfare clause is a
qualifier on the taxation power; it limits government to taking taxes for the 'general', as opposed to the 'specific', welfare of citizens. That means whatever the money is spent on must be for purposes that benefit society as a whole, and not just certain individuals, classes or 'interest groups'.
By embracing corporatism, and creating government does just that, that caters to special interests, rather than the general welfare, we create the situation that tempts us to implement discriminatory taxation. We become pre-occupied with figuring out who is benefiting and worrying about how to get them to pay 'their share'.
In my view, if a given government service can't be thought of as benefitting everyone more or less equally, it probably shouldn't be a government service. Likewise, we should strive to ensure that everyone
pays more or less and equal share in the financing of government. This is an ideal, of course, and there are practical limits. No law or state service will benefit everyone perfectly equally, and not everyone will be able to pay an equal share of the tax burden (eg the poor, the incarcerated, etc..). But in general that should be the goal, and we should try to avoid government that ends up playing off special interests against each other, with all of us in a struggle to get the 'other guy' to shoulder more of the burden, while increasing our own benefits.