It's happening on his watch...he gets the blame. That's how it works with Presidents. They take the credit when good things happen while they are in office (even when they had nothing to do with it happening) so they get blamed when bad things happen while they are in office (even when it's not their fault). If that is too much for them to handle, they need to resign. It's what a former boss of mine loved to say; "I didn't say it was your fault, I said I was going to blame you."