The U.S. chief of state, the president, wasn't supposed to be as powerful as the job presently entails. The drafters of the Constitution conceived of the presidency as having clearly defined duties and limited powers. Congress, with dozens of members elected by the different states, was where the real authority and the will of the people lay. Since then, the executive branch has become much more formidable.

Who Is the Chief of State?

The chief of state for any country is the head of the government. In the United States it's the president, but around the world it includes generals, dictators, prime ministers and monarchs. In the U.S. and many other nations it's a powerful position, but that's not always the case. Queen Elizabeth II is the United Kingdom's current head of state, for instance, but her actual power over the government is limited.

Even among countries where the chief of state is chosen democratically, there are lots of variations. Some countries elect the chief of state, as the U.S. does. In Germany, the chief of state is the chancellor. She is the leader of the majority party in Germany's Congress, the Bundestag. Germans vote for the party's candidates rather than for the chancellor's slot itself.

What Does the Chief of State Do?

The U.S. Constitution divides federal authority between the Supreme Court, Congress and the executive branch, while reserving some rights for the American people and state governments. The power of the executive branch is vested in the president, the U.S. chief of state. Technically, people don't vote for the president, but vote for electors in the electoral college who then vote to choose the president. Article II of the Constitution lists the president's duties and powers:

• Serving as commander in chief of the U.S. military.
  

• Requiring the heads of the various executive branch departments –

  Justice, Education and Defense, for instance –

  give him their opinions, in writing, on any subject related to their offices.
  The president can issue pardons for federal crimes, except in cases of impeachment.
  The president negotiates treaties, though two-thirds of the Senate has to vote for a treaty to make it law.
  The president nominates all federal officers whose appointments aren't otherwise covered in the Constitution. Article II specifically says it's the president's duty to appoint ambassadors and Supreme Court judges. The Senate has to approve appointments, unless they're made while the Senate is in recess.
  The president has to address Congress on the State of the Union "from time to time," which is why there's an annual State of the Union address.
  The president recommends Congress pass bills "he shall judge necessary and expedient." He has to sign bills Congress passes to make them into law. If he vetoes the bill, Congress can override him with a two-thirds majority vote.
  In extraordinary circumstances, the president can summon the House, the Senate or both into session. This was written when they didn't work year-round as they do today.
  The president receives ambassadors and public officials from other nations.
  The president "shall take care that the Laws be faithfully executed."
  

While parts of Article II are clear, other clauses have kept legal scholars arguing over the president's duties for more than 200 years.

How Power Grows

Almost from the first, American presidents began expanding the scope of their duties. For example, the Constitution gives the president the duty to receive foreign ambassadors. In practice, this doesn't mean the president invites them to dinner; it means that they can't represent their government in the United States without the chief of state's approval. The duty to receive gives the president the duty to refuse diplomats as well. In a civil war or revolution overseas, the president can show support for one side by supporting their ambassadors and refusing the other side's diplomats. The president can also recognize a newly formed country by accepting its ambassadors.

Another example of how the duties of the chief of state have grown is the Justice Department. The 1789 Judiciary Act created a federal attorney general to handle federal prosecutions. In 1870, Congress created the Justice Department to cope with a growing number of federal cases. In the 20th century, rather than use Secret Service agents or private detectives on federal investigations, the government created the FBI to handle the work. The end result is that the president's duties include overseeing "the world's largest law office."

Likewise, the president's duty to "make treaties," in the words of Article II, says nothing about the details of negotiating a treaty. By the 1930s, though, it was accepted that the president's duties include the full and sole authority to handle negotiations. The Senate can vote to reject a treaty or propose amendments. It cannot participate in negotiations or even demand the president provide any details about how negotiations are going.

Becoming Commander in Chief

As war is one of the government's most costly functions, serving as commander in chief is one of the president's most important duties. It's also one of the most controversial. Did the Constitution give the president this duty solely to establish the military are under civilian control? Or does it grant him vast powers in time of war?

As commander in chief, the president and the Department of Defense sets the military budget and the priorities for spending it, though Congress has to approve the budget. More soldiers? More tanks? More nuclear missiles? Should we station more troops in Europe or in Japan? Figuring out our military priorities is part of the president's duties.

The president's duties do not include plotting battle tactics; that's for the generals and the troops in the field. The president does have the duty to declare war and authorize the use of troops against the enemy. Whether the White House can do that without Congressional approval is one of the controversies about the commander in chief role. The 1973 War Powers Resolution says the president can commit troops for 60 days, but then has the duty to withdraw them unless Congress signs off. The presidents since then have considered the resolution an unconstitutional restriction on their authority, so they've ignored it.

Presidents have also interpreted their commander in chief duties as giving them powers on the home front. During the Korean War, for example, President Harry Truman tried to prevent a nationwide steel-mill strike by having the government take over the mills. His argument was that with steel needed for military production, his duties as president and commander in chief justified the seizure. When the issue went to trial, the Supreme Court ruled that the chief of state's duties did not cover nationalizing the mills.

Acting Through the Cabinet

Over the centuries, Congress has added to the president's duties. Every time Congress creates a Cabinet department, such as Justice, or Housing and Urban Development, that department's mission becomes a new presidential duty. Even though employees at HUD, for example, don't ask the Oval Office to green-light every decision, they're considered to be carrying out the president's duties. Their actions, as long as they're within the law, are the president's actions.

• The Department of the Interior has the duty to manage national parks, conduct scientific research and manage natural resources.
  
• The Department of Labor's duties include promoting workplace safety and protecting employees from wage theft and harassment.
  
• HUD's duties involve making it easier for Americans to buy or rent homes.
  
• The Department of Health and Human Services conducts health and social science research, fights disease outbreaks, and administers Medicare and Medicaid.
  
• Homeland Security prevents terrorist attacks and helps with recovery when attacks take place.
  

This Executive Branch bureaucracy has vastly expanded the president's duties and powers.

Executing the Laws

The Constitution says the president's duties include seeing that U.S. laws are "faithfully executed." James Madison described this as the chief of state's most important duty. But like the president's other duties, the U.S. chiefs of state have disagreed over what it means. President James Buchanan believed the Southern states seceding in 1860 violated the law, but didn't think he had a duty to intervene. Abraham Lincoln believed ending secession was part of his duties. A few decades later, President Theodore Roosevelt believed he could take any action that didn't break the law and still fulfill his faithful-execution duty.

Each president derives some understanding of this duty from the way other presidents have interpreted it. Carrying out this duty also requires the president to interpret the law and the Constitution. If Congress authorizes $10 million in spending for a new health department project, for example, does the president's duty require him to spend it? Some presidents have argued that while they can't spend the money on something different, they can refuse to spend it at all.

The Chief of State Appoints Officials

The president appoints many officials: high ranking military members, ambassadors, department heads and federal judges. Like running executive branch departments, presidents don't have to personally select or vet nominees. Instead, they can ask for recommendations and advice from subordinates, non-governmental groups and members of Congress.

This duty is a tremendous power. Decisions made by federal judges, particularly Supreme Court judges, on how to interpret the law can shape the rights and restrictions of American citizens for decades.

The Big Picture

Politicians, constitutional scholars and regular citizens have often tried to sum up the duties of the chief of state more simply than Article II does. Ever since the 9/11 attacks, many politicians have defined the president's primary duty as protecting the security and safety of American citizens. A counter-argument is to point to the president's oath of office, which says the president "will to the best of my ability, preserve, protect and defend the Constitution of the United States.” Therefore, that must be the president's number one obligation.

There's no conclusive answer, because terms like "security and safety" or "defend the Constitution" leave a lot of room for interpretation. If the president deprives someone of their Constitutional rights on the grounds they're a threat to public safety, does that fail the duty to the Constitution? Is the need to protect Americans a higher priority?

Presidents don't get to define their duty and responsibility all by themselves. As in the steel-mill case, questions about presidential authority, power and duty have often wound up in the courts.

During World War II, for instance, President Franklin D. Roosevelt signed an executive order authorizing the military to force Japanese-Americans to leave the West Coast. Many of them wound up imprisoned in internment camps for the duration of the war. Several Japanese-Americans sued, challenging the president's authority to issue such an order. In the Supreme Court's Korematsu decision, the justices ruled that the president acted within his authority. Although the decision has never been overturned, Korematsu is almost universally agreed to be one of the Supreme Court's worst calls. At the time that didn't matter. The court had confirmed the president's duties extended to interning people, and that it didn't violate his duty to the Constitution.