Some people find certain numbers to be of great significance. For example, the Chinese find the number 8 to be very lucky. Americans find 13 to be very unlucky.

The big number this week is 47, as in the 47 percent of irresponsible, freeloading voters that Mitt Romney decided months ago he can’t and won’t try to win over.

Turns out 47 percent has a historical place in presidential campaign history. President Richard M. Nixon may have been the first to employ it, using it to great effect 40 years ago in his 1972 reelection campaign against Sen. George McGovern....