The most important issue in this November's presidential election isn't Iraq or terrorism or the economy, though it plays into all three. The most important issue is presidential power.

In our history and civics classes, we're taught that the genius of the Constitution is the checks and balances it imposes on the three branches of government. The founders understood that each branch — the president, the Congress and the courts — would seek to expand its power. They then set up a system that not only acknowledges man's desire to accumulate power but also one that harnesses that desire and uses it to keep any one branch from becoming too influential.

That system has mostly served us well. But an important new book details how the delicate balance of power in the federal government has been unraveling for nearly a century now, and underscores how important it is that we elect a president this November who understands the constitutional boundaries of the office.

Unfortunately, that isn't likely to happen.

"The Cult of the Presidency" by the Cato Institute's Gene Healy (I should disclose that Healy is a friend and former colleague) provides a history of the office of the presidency. It's a fascinating narrative of how the office that was meant to be little more than an administrator of the nation's laws (George Washington referred to it as "chief magistrate") has grown into the equivalent of an elected monarch.

It's a curious thing in America that each July we celebrate how the founding fathers threw off the shackles of an oppressive monarchy, that we favorably compare our republican system of governance with the world's tyrants, dictatorships and monarchies (and rightly so) -- and yet we then celebrate those American presidents who most behaved like tyrants, monarchs and dictators.

Presidents like Woodrow Wilson, Teddy Roosevelt, Franklin Roosevelt and Harry Truman are regularly put at the top of lists of America's greatest presidents. This is true when both historians and the American public at large are polled. Yet these are presidents who did everything they could to expand the power of their offices, to extend the sphere of influence of the federal government and to bully through policies that met inconvenient hurdles otherwise known as checks and balances.

Woodrow Wilson ran for president on a peace platform, then dragged us through the bloody trench carnage of World War I. Oh, and he imprisoned thousands of critics and war protesters in the process. Teddy Roosevelt once lamented that he didn't have a war during his administration to make him great, and compared the stakes of his third-party run for the White House to the rapture and second coming of Jesus Christ.

Franklin Roosevelt broke the tradition set by George Washington of serving just two terms. When the Supreme Court rebuffed his attempts to pass unconstitutional legislation, he tried to expand the number of justices on the Court to ensure a friendly majority. Harry Truman was the first president to pull America into a protracted war without first consulting Congress. He then sought to nationalize private companies to ensure that war was properly outfitted.

These are odd men to call heroes.

Inexplicably, the presidents who knew and understood their constitutional limits, who respected those limits and who generally took a more laissez-faire approach to government get short shrift — even derision — from historians.

Men like Calvin Coolidge, Warren Harding, Rutherford B. Hayes and Grover Cleveland merely exhibited what Healy calls "stolid, boring competence." Historians loathe them, Healy writes, because they had the audacity to "content themselves simply with presiding over peace and prosperity" and not seek to remake the world in their own image. The nerve of them.

Today, the president oversees 1.8 million federal employees. The federal government is America's largest employer. Moreover, we today expect much more from the president than merely to enforce the nation's laws. We expect him to console us in times of tragedy or natural disaster, to inspire us in times of war. Some even look to the president for spiritual guidance. The enormity of the office grows more unsettling when you consider the set of skills and traits it takes to get elected. As Healy explains, the long, brutal, expensive primary and general election process selects people with massive egos, people willing to subject themselves to all sorts of abuse in the pursuit of power and people willing to accept favors from all sorts of interests as they ascend from office to office — favors from people who generally expect to be repaid.

George Washington set perhaps the most important precedent in the history of the idea of a constitutional republic when he declined to seek a third term. He could have been a king if he'd so chosen. Despite achieving myth-like reverence and adulation while still in office, Washington had the humility and the foresight to understand the importance of leaving power on the table. Doing so not only limited his own power but began the voluntary two-term tradition that lasted 140 years.

While both Barack Obama and John McCain have in some way acknowledged that the Bush administration has dangerously pushed the limits of executive power, neither has indicated exactly what powers, if elected, he would give back or what steps he'd take to make sure those powers aren't later invoked by a successor.

Perhaps it's too much to hope for another George Washington. Instead, this November, it looks as if our choices are a man who styles himself after John F. Kennedy and a man who idolizes Teddy Roosevelt.

That doesn't bode well for the next four years, or for the imperial presidency's continuing threat to American democracy.

Radley Balko is a senior editor for Reason magazine and maintains at Web log at TheAgitator.com.