This history of presidential victory is the source of presidential failure today. It is a replay of the histories told by the Greeks and Romans. The power amassed by presidents over 150 years allowed the office to outperform its peers, and serve the nation, but now the scale of power undermines the office and its purposes.

The details recorded in presidential calendars make this graphically clear. Managing enormous power drives presidents away from the issues that matter most, and the values they care most about. They are not leading because they are only reacting. Trying to run the world, presidents jump continuously from issue to issue, in perpetual crisis mode. They are frantically struggling to keep up, even as they acquire new tools (from cybertechnologies to unmanned drones) that expand their reach.

A comparison between Roosevelt and Kennedy, only 20 years apart, shows the transformation of the presidency with its postwar global scale—a leadership challenge that only grows worse with each new administration and multiplying crises and demands. Roosevelt had time to focus, think, and plan. Kennedy could barely keep up. His successors struggle just to stay afloat.

As these and other calendars reprinted in The Impossible Presidency show, contemporary presidents are unable to invest deeply in understanding issues or pursuing core goals. Everything is about putting out fires and kicking big problems—like health care, inequality, the environment, debt, and failed states—down the road. In a reversal of George Washington’s modesty, presidents have become emperors who ride far from the crowds in black SUVs and white Air Force One chariots, striving every day to meet the unending demands on their power.