The American presidency is broken, and everyone seems to know it. Many of its challenges are, by now, familiar. Presidents are bombarded by a 24-hour news media, populated by journalists looking to expose any appearance of negligence or wrong-doing. The range of crises—foreign and domestic—has expanded as the country has grown. And yes, presidents are more isolated than ever before.

But the country has long had a vicious media culture, a wide array of daily crises, and isolated leaders. Presidents including Andrew Jackson, Abraham Lincoln, and Franklin Roosevelt all complained about these problems—and to greater or lesser extents, succeeded in spite of them. So why is the contemporary office doomed to failure? The fundamental problem is that the expectations surrounding presidential power have created an unending series of demands, at home and abroad. Presidents are simply trying to do too much in too many places.

In September, I published The Impossible Presidency, a history of the American presidency, and its rise and decline over two centuries. In April, John Dickerson published an article in the Atlantic that recounted many of the same problems with the office. Dickerson and I both agree that even if a paragon of integrity and wisdom replaces the current commander-in-chief, the new president will struggle to unite and lead the country, but we part ways as to why that’s so. Dickerson’s article is entirely focused on developments since the Cold War. The sources of failure, though, have much deeper and earlier origins, which is why the longer history of the presidency is crucial for understanding contemporary problems.

Prior generations of Americans have recognized the limits of the office. The nature of the presidency has evolved through American history, and what it has meant to be president—including popular expectations and daily behaviors—has varied. On three occasions in the past, Americans have had to define the presidency so that it could serve the national needs of their own moment. Today, Americans have inherited a presidency built for another time, and must again reform it.

When George Washington became the nation’s first president, no one really knew what to expect. Disagreement among the Founders had left Article II of the Constitution, on the powers of the presidency, extremely vague. Hamilton wanted something closer to a king; Madison envisioned a creature of the legislature, closer to a prime minister. ...