Federal regulation of porn and pot rely on the same open-ended interpretation of the Commerce Clause the New Deal and all of Obama's stimulus and reform programs do. As long as he keeps the Republicans talking about wanting federal regulation of those under the "substantial effects" doctrine there's no grounds for them to make any kind of constitutional challenge to his programs.
Exactly.
Republicans want their un-constituional cake and eat it too.
Respondents Diane Monson and Angel Raich use marijuana that has never been bought or sold, that has never crossed state lines, and that has had no demonstrable effect on the national market for marijuana. If Congress can regulate this under the Commerce Clause, then it can regulate virtually anything–and the Federal Government is no longer one of limited and enumerated powers.