The only criticism that can be reasonably leveled at Obama over the BP flap was the fact that A) I believe he’s been the largest recipient of campaign donations from BP, and B) his regulators gave BP a pass on safety inspections.
Once the explosion actually happened, there’s very little a President can do, and I’m glad Obama hasn’t tried to micro-manage it.
That said, Bush took way too much blame for Katrina, and Obama heartily piled on him over that. So now he gets to find out what it means when ‘the buck stops here’ - you get credit for things you didn’t do, and blame for things you’re not responsible for. That’s one of the burdens of being President.