This week, California will have four different governors in four days.
Per the state constitution, when the governor leaves the state for work or personal business, someone has to fill in as acting governor. But Gov. Jerry Brown isn't the only top official leaving the state this week — the lieutenant governor and the state Senate president pro tem are traveling too. Both of them will have a turn as acting governor before they leave, when the job will fall to California's Assembly speaker for nine hours, before Brown returns.
While Joe Biden doesn't assume presidential authority every time President Obama leaves the country, there is precedent for turning the White House over to an acting president. The 25th Amendment grants the vice president and Cabinet members the power to declare a president disabled, transferring presidential responsibilities to the vice president. It also allows the president to declare himself temporarily unable to perform his duties. This last provision has been invoked by only three presidents in American history — all of whom did so because of their large intestine.
On July 13, 1985, George H.W. Bush served as acting president for about eight hours while Ronald Reagan had surgery to remove cancerous polyps from his colon. (After all, being the president is kind of difficult when you're under anesthesia.) On June 29, 2002, Dick Cheney served as acting president for two hours while George W. Bush underwent a colonoscopy. The procedure took place just nine months after the Sept. 11 terrorist attacks, and Bush told reporters that he wanted to be "super cautious." Another colonoscopy five years later made Cheney acting president again for two hours.
Acting presidents can do a whole lot without actually holding the office of the president. Aside from the usual "powers and duties" given to the president under Article II of the Constitution, acting presidents can sign bills into law or ask Congress to declare war.
The concept of an acting president is fairly new in the nation's history. Before the 25th Amendment was ratified in 1967, a legal framework for temporary transfers of power didn't exist. Until the middle of the 20th century, presidents who, by today's standards, would be considered unable to do their jobs at one point or another did not see major lapses in health as a hindrance to governing the nation.
When a massive stroke in 1919 left Woodrow Wilson partially paralyzed on the left side, the president didn't step down. He instead finished out his second term with little time in the public eye. In 1955, Dwight Eisenhower had a heart attack and spent seven weeks recovering. A year later, he spent six days in the hospital because of a bowel obstruction. And a year after that, he suffered a mild stroke. Eisenhower maintained presidential authority during all three situations.
Nowadays, to temporarily transfer his constitutional powers and duties to the vice president, the president must write a letter to the House speaker and the Senate president pro tempore. He must also write a second note reasserting his power once he can return to office. (Here's how these discharge and resumption letters look.) If Obama were ever to follow in Bush's steps, he would find himself in a comical situation: writing about his colon health to the man who's suing him.