The American presidency is designed to disappoint. Each candidate must promise things that are beyond his power to deliver. No candidate could expect to be elected by emphasizing how little power the office actually has and how voters should therefore expect little from him. So candidates promise great, transformative programs. What the winner actually can deliver depends upon what other institutions, nations and reality will allow him. Though the gap between promises and realities destroys immodest candidates, from the founding fathers' point of view, it protects the republic. They distrusted government in general and the office of the president in particular.
Congress, the Supreme Court and the Federal Reserve Board all circumscribe the president's power over domestic life. This and the authority of the states greatly limit the president's power, just as the country's founders intended. To achieve anything substantial, the president must create a coalition of political interests to shape decision-making in other branches of the government. Yet at the same time -- and this is the main paradox of American political culture -- the presidency is seen as a decisive institution and the person holding that office is seen as being of overriding importance.
Constraints in the Foreign Policy Arena
The president has somewhat more authority in foreign policy, but only marginally so. He is trapped by public opinion, congressional intrusion, and above all, by the realities of geopolitics. Thus, while during his 2000 presidential campaign George W. Bush argued vehemently against nation-building, once in office, he did just that (with precisely the consequences he had warned of on the campaign trail). And regardless of how he modeled his foreign policy during his first campaign, the 9/11 attacks defined his presidency.
Similarly, Barack Obama campaigned on a promise to redefine America's relationship with both Europe and the Islamic world. Neither happened. It has been widely and properly noted how little Obama's foreign policy in action has differed from George W. Bush's. It was not that Obama didn't intend to have a different foreign policy, but simply that what the president wants and what actually happens are very different things.
The power often ascribed to the U.S. presidency is overblown. But even so, people -- including leaders -- all over the world still take that power very seriously. They want to believe that someone is in control of what is happening. The thought that no one can control something as vast and complex as a country or the world is a frightening thought. Conspiracy theories offer this comfort, too, since they assume that while evil may govern the world, at least the world is governed. There is, of course, an alternative viewpoint, namely that while no one actually is in charge, the world is still predictable as long as you understand the impersonal forces guiding it. This is an uncomfortable and unacceptable notion to those who would make a difference in the world. For such people, the presidential race -- like political disputes the world over -- is of great significance.
Ultimately, the president does not have the power to transform U.S. foreign policy. Instead, American interests, the structure of the world and the limits of power determine foreign policy.
In the broadest sense, current U.S. foreign policy has been in place for about a century. During that period, the United States has sought to balance and rebalance the international system to contain potential threats in the Eastern Hemisphere, which has been torn by wars. The Western Hemisphere in general, and North America in particular, has not. No president could afford to risk allowing conflict to come to North America.
At one level, presidents do count: The strategy they pursue keeping the Western Hemisphere conflict-free matters. During World War I, the United States intervened after the Germans began to threaten Atlantic sea-lanes and just weeks after the fall of the czar. At this point in the war, the European system seemed about to become unbalanced, with the Germans coming to dominate it. In World War II, the United States followed a similar strategy, allowing the system in both Europe and Asia to become unbalanced before intervening. This was called isolationism, but that is a simplistic description of the strategy of relying on the balance of power to correct itself and only intervening as a last resort.