As George points out, executive power has gotten out of hand, as seen with the Obama Administration’s efforts to regulate greenhouse gases without clear statutory authority.
This excessive executive power can be attributed to the demise of the non-delegation doctrine. The idea behind the doctrine is Congress can’t delegate away its legislative power to the executive branch. If there were a real non-delegation doctrine still, excessively broad legislation (e.g. Clean Air Act) that allows an agency to do pretty much whatever it wants would amount to delegating away legislative power.
Unfortunately, the doctrine is close to being dead. The fault lies with Congress and the judicial branch, not the executive branch.
