Quite interesting that Clinton went after Obama specifically on energy tonight:

You know, the energy bill that passed in 2005 was larded with all kinds of special interest breaks, giveaways to the oil companies. Senator Obama voted for it. I did not because I knew that it was going to be an absolute nightmare. Now we're all out on the campaign trail talking about taking the tax subsidies away from the oil companies, some of which were in that 2005 energy bill.

A perfectly legitimate point, and a sharp one.