Modern vice presidents can trace much of their political influence to the broad reforms that Jimmy Carter and Walter Mondale made to the second-highest elected office in the late 1970s.

Tariffs have been applied over the years to protect homegrown industries and target competitors who are seen as using unfair trade practices. They impose costs on both importers and exporters and had been in decline until the recent U.S.-China trade war.

The threat of climate change and the rise of China have prompted renewed debate about the U.S. government’s role in shaping the economy.

Sub-Saharan Africa is home to many of the world’s longest-ruling heads of state. Pro-democracy advocates have at times successfully stopped presidents from extending their mandates, but the authorita…