Success in politics -- and in political predictions -- depends on the ability to distinguish between old rules of thumb that don’t apply anymore and old rules of thumb that do.
Take the old rule that an officeholder’s chances of re-election depend on what James Carville in 1992 took to calling “the economy, stupid.”
That used to be a real thing. The Great Depression took President Herbert Hoover down from 58 percent of the vote in 1928 to 40 percent in 1932. The return of economic growth enabled President Franklin Roosevelt to increase his 57 percent in 1932 to 61 percent in 1936 and then to win re-election twice in the shadow of world war in the 1940s.
Amid recession, President Ronald Reagan’s job approval sunk to 41 percent in January 1983. Amid surging growth, it rose to 58 percent in October 1984. A month later, he won 59 percent of the popular vote and carried 49 states.