The Hawley-Smoot Tariff (or Smoot-Hawley Tariff Act) was signed into law on June 17, 1930, and raised U.S. tariffs on over 20,000 imported goods to record levels, and, in the opinion of most economists, worsened the Great Depression. Economists have now generally regarded this Tariff Act (i.e., tax increase on imported goods) as the greatest policy blunder in American economic history, coming as it did after the 1929-30 recession and preventing the economy from a full, natural recovery which had already started by the Spring of 1930. Many countries retaliated with their own increased tariffs on U.S. goods, and American exports and imports plunged by more than half.
During the 1992 Presidential Debate, Ross Perot warned of a "giant sucking sound" to describe job losses to Mexico if NAFTA was signed. During a debate on CNN, Al Gore presented Perot with a framed portrait of Congressmen Smoot and Hawley. The Clinton Administration subsequently won the election and passed NAFTA, which was considered for years to be a fantastic bipartisan achievement.
More trade discussion from my favorite economist Greg Mankiw on the NY Times.