Reagan won 49 states and lost Minnesota by a whisker. Mondale won his home state and DC. Popular vote was 59-41. Electoral was a whopping 525-13.
But Cavuto forgets that Reagan lost senate seats continually and finally lost the Senate in 1986. He never did get the House. Mandates are in the eye of the beholder.
Bush has coattails which is very, very important given his modest reelection mandate. Considering he turned at least one, perhaps, two Gore states (perhaps net +1) and broke the 50% mark--unlike Clinton, I would not say Bush anyone could claim he has no mandate.
The "largest number of voters" of all presidential candidates is more a talking point preemptive strike in light of Florida and Kerry's inability to concede in a timely manner rather than of useful value since the nation's population has increased since even the Reagan reelection 20 years ago.