Obviously Reagon won by a landslide in 1984 when he carried 49 states, got 525 Electoral votes a (compared to Mondale’s 13), and had an 18 percentage point lead in the popular vote.
But if Obama should win by 8 points and get 364 EVs, would that be a landslide?
Is there a specific definition of landslide as it relates to elections?
It would depend on your view. For instance if Obama won every state but Maine and Vermont it’d be a landslide. But if Obama won every state except California and Texas it may not be, 'cause those are the two most populas states.
It has no quantative meaning at all. In 2004, many pro-Bush commentators claimed a “landslide”. 50.7% vs 48.3% popular vote and 286 vs. 252 electoral vote (which hung on a single questionable tally in Ohio). (It was also the closest popular vote for a winning incumbent.)
Since the winner of the 2008 vote is likely to top all those (as well as a new all time record for most votes received) by quite a bit, expect the same people to claim “not a landslide”.
Back in 1984, when the election was a foregone conclusion and the pundits had lots of time to blather, a couple of them got into an argument over Reagan’s 59% of the popular vote really constituted a “landslide.” They felt 60% was the magic number. By that measurement, the only landslides in the last 100 years would be Harding (1920), Roosevelt (1936), Johnson (1964) and Nixon (1972). That’s about 15% of all the presidential elections of that period.
But it’s a lot easier to get 60% of the electoral vote than popular vote. The highest 15% of electoral vote percentages during those elections ranged from 91% (Reagan 1980) to 98% (Roosevelt 1936.)
So let’s say from an electoral vote standpoint you need 90% of 538 EV. That’s about 484.
It seems to be an old saying/joke/spin that “A majority of one is a landslide”. IIRC JFK or his father said it, and Jim Barrett of McCain’s NH campaign said it in the primary,
Lyndon Johnson acquired the ironic nickname “Landslide Lyndon” after he won his 1948 Senate campaign by an official tally of 87 votes at a time when the population of Texas was over seven million.