I think pricing carbon and activities that in effect cause social externalities is important. We've got to get the prices right, and therefore I'm not opposed to pricing any product that in effect generates negative externalities by imposing a tax on it. That's what excise taxes are all about. They're really not taxes; they're the government attempting to get the price of those products correct so the market can perform its allocated efficiency function.
You know the politics of it as well as I do, so I won't go into that. I just don't think there's a case for not doing it. I've never heard the case for not doing it, frankly.