A heartbeat away: the vice presidency has long been the butt of jokes, but the job is much more important than it used to be.

• Author: Smith, Patricia
• Position: NATIONAL

Hillary Clinton's recent bout of pneumonia didn't last long, but it put the issue of presidential health front and center in the race for the White House.

Her illness, coupled with the nominees' ages--Clinton, the Democrat, is 69; Donald Trump, the Republican, is 70--has prompted a closer look at the role of the vice president, who is first in the line of succession if a president dies or is unable to continue to serve in office.

"It should remind people of the importance of the two vice presidential candidates, and whether they are appropriate presidential successors based on their experience, skill, character, and substantive views," says Joel Goldstein, a law professor at St. Louis University and an expert on the vice presidency.

Clinton's running mate, Tim Kaine, 58, of Virginia, was elected to the U.S. Senate in 2012, where he now serves on the Foreign Relations Committee. Before that, he was Virginia's governor for four years.

Trump's choice for vice president, Mike Pence, 57, spent 12 years representing Indiana in the House of Representatives before becoming the state's governor in 2013.

The conventional wisdom is that most voters don't pay much attention to who's on the bottom of a presidential ticket. But they probably should, since many of these understudies have ended up stepping into the lead role.

Of the 47 vice presidents since 1789, 14 have become president. Nine got the job without being elected, when the president died in office or resigned. For example, John Tyler became president in 1841 when William Henry Harrison died of pneumonia a month after his inauguration; Theodore Roosevelt got the top job after William McKinley was assassinated in 1901; and in 1974, Gerald Ford moved up when Richard M. Nixon, facing impeachment over the Watergate scandal, became the first and only president to resign.

Consolation Prize

Nevertheless, the vice presidency has long been the target of jokes--often from vice presidents themselves. John Adams, the first to hold the job, called it "the most insignificant office." And John Nance Garner, Franklin D. Roosevelt's vice president for his first two terms (1933-41), said the job wasn't worth a bucket of warm urine. (Actually, he used a word we can't print here.)

Some of the ridicule has stemmed from how the office was conceived. Aside from taking over for a president who dies or can no longer serve, the vice president's responsibility under the Constitution is just to preside over the Senate and break tie votes. Other than that, the job wasn't given much thought, says Stanley Katz, a constitutional historian at Princeton University.

In fact, in the early days of the U.S., the vice presidency was merely a consolation prize. The vice president wasn't a running mate but a runner-up: The candidate who finished second in the presidential election became the vice president. This meant that the president and vice president were political rivals, as was the case in the election to succeed George Washington in...