Liberals frequently accused George Bush of violating the Constitution. In Bush's case there was at least a legal argument that Bush was properly exercising legal authority, and it was up to the courts to decide who was correct. (In fact, there is a strong legal argument that given the separation of powers, the courts are not empowered to decide what executive powers are.) And, Bush usually went to Congress to get their approval, even though the Democrats would often later claim they were misled, or didn't understand what they were doing (entirely plausible). Obama, on the other hand, appears to simply ignore the Constitution (which he has said he doesn't agree with) and laws he doesn't like (such as bankruptcy laws).