However, it is worth noting — as political scientist Graham Dodds does in his recent book Take Up Your Pen — that the formal executive order is only one mechanism for presidential unilateral action. Executive orders can be powerful, but they have their substantive limits; plus, most of them are published openly in the Federal Register and follow a standard formulation sequence, neither of which always suit presidential preferences.
In her lengthy 2001 law review piece “Presidential Administration,” future Supreme Court Justice Elena Kagan detailed several more vehicles for unilateralism, centering on the use of administrative memoranda (to one or more departments) and rule-making prompted by the Executive Office. But even more sweeping was a Congressional Research Service study, updated in 2008, which found more than 20 formal types of presidential directive. Since the CRS count did not include administrative memoranda, written determinations, signing statements or regulatory action, the total seems to be closer to 30 than 20.
So the jury is still out on whether Obama has expanded the use of unilateral action as compared to his predecessors. But thanks to their wide-ranging administrative creativity (plus his own), he has plenty of ways to do so.