there are a whole range of things he can't do, he can't direct congress, he can't appoint who he wants freely, he can't make treaties with whom he wants when he wants, he can't start wars  if he wants to start wars   all these controls are on the president but what i, what er newstat is saying is, over and above that, even in the areas where he appears to have constitutional authority, as a matter of practice it's very difficult for the president to exercise his authority and when the president does exercise his authority he does so at great cost to himself.