Bryan Faler at the Washington Post runs more numbers from the mandate beat:

Bush’s unofficial three-percentage-point margin of victory, for example, was the fifth smallest since 1920. John F. Kennedy won in 1960 with 0.2 percent more votes than Richard M. Nixon. Nixon, in turn, won in 1968 with a slim 0.7 percent advantage over Hubert H. Humphrey. In 1976, Jimmy Carter defeated Gerald R. Ford by 2.1 percent. In 2000, Al Gore won the popular vote but lost the electoral one. Conversely, 10 of the previous 21 presidential races were won by at least 10 percentage points — and five of them were decided by more than 20 points.

Bush’s chunk of the popular vote — unofficially, 51 percent — also places him in the middle of this historical pack. Thirteen of the winners of the previous 21 elections won a larger share of the vote. Lyndon B. Johnson won the highest percentage, when he swamped Barry Goldwater in 1964 with 61.1 percent. Bill Clinton won with the lowest, when he took 43 percent in 1992. Bush, however, is the first to win a majority of the popular vote since 1988.

As I wrote a few days ago, Faler is right that Bush’s victory certainly doesn’t compare with supposed “mandate” elections of the past, but that may not matter. On NPR tonight, I heard Mara Liasson says Bush will “begin to enact” his second-term agenda — phrasing that ignores Congress and assumes he will be successful — and the liberal folks at Media Matters have tracked a bunch of reporters explicitly saying Bush has a mandate over the last week. If enough people buy into the idea, well, then it’s a “mandate” regardless of what happened on Election Day.