It's impossible now, but it will certainly be possible if political cards get reshuffled in an election. The two important questions would be:
1) Will the public be mollified by tinkering with the existing taxcode, or do they demand fundamental change to the way we raise revenue.
2) Whether we just ammend the current tax code or start anew, what mechanisms can be put into place to defend against a regrowth of tax code complexity? We had the reforms of 1986, and here we are with a still more complex and impenetrable system. No one can possibly understand all of the present law. Supermajorities, a constitutional amendment--something should be done to keep the tax code "clean" for the long term so businesses and individuals can plan, and so we don't end up here again. If we decide we need more or less money then change the tax rates, but can we please not try to use the tax code to micromanage the economy and people's behavior?