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 1796: Thomas Jefferson became vice president after losing the presidential election to his nemesis, John Adams.
The system in use today—in which the president and vice president run on a single ticket—took effect with the ratification of the 12th Amendment in 1804.
Even with that change, however, most presidents until recently shared little power with their vice presidents, who were often left to perform mostly ceremonial duties.
The shift began during the presidency of Bill Clinton in the 1990s and continued under his successor, George W. Bush. By all accounts, Presidents Clinton and Bush gave Vice Presidents Al Gore and Dick Cheney more power and influence than any other vice presidents in American history.
For the past eight years, President Obama’s vice president, Joe Biden, has carried on that tradition. He attends Obama’s daily national security briefing and all important foreign policy meetings. It’s a far cry from the days during World War II when FDR’s vice president, Harry S. Truman, wasn’t even told about the top-secret development of the atomic bomb.
“It’s certainly a good deal more than just going to state funerals these days,” says Lee Edwards, a presidential scholar at the Heritage Foundation.
Clinton has said she wants her VP to serve as a sounding board, and Kaine’s strong record on immigration issues and his fluent Spanish could help get immigration reform passed. Trump says he expects to lean on Pence for his Washington expertise.