As today's New York Times observes, the Obama administration's policy of drone strikes provides a troubling example of unconstrained executive power. Senator Angus King (I-ME) put it well when he criticized a regime in which the president is "the prosecutor, the judge, the jury and the executioner."
The article considers the possibility of a special "drone court" as an external check on the president and identifies the problems with that approach. Indeed, experience teaches us that external checks on the executive branch do not work very well. Both Congress and the courts generally have acquisced or even abetted the expansion of presidential power.
Hence, in my forthcoming book, Two Presidents Are Better Than One: The Case for a Bipartisan Executive Branch (NYU Press), I observe that we need a strong internal check on the executive branch and that a two-person, bipartisan presidency would provide the right kind of check. As the founding fathers recognized and decision making research confirms, policy is better made when people with different perspectives work things out together.
George W. Bush’s invasion of Iraq and Lyndon B. Johnson’s escalation of the Vietnam War are illustrative—a single misguided decision maker can make choices very harmful to the country. In the words of Woodrow Wilson, the “whole purpose of democracy is that we may hold counsel with one another, so as not to depend upon the understanding of one man.”
Of course, there are many questions raised by a two-person presidency. How would two executives make decisions, why wouldn't they end up fighting with each other, etc.? These are all good questions, and I answer them in Two Presidents. For a summary of my answers, see Chapter 1.