Some say Bush policies affect us, therefore they bash. Why don't they bash any of the 42 others?

We had 42 presidents before Obama, its 42 because one was elected twice to nonconsecutive terms. I think it was grover cleveland or chester arthur.Most if not all have done things that still effect us today. I wonder why the liberals never mention any president in the negative, except Bush Jr.? It could be they are afraid of facts.