I was messing around with the trendlines from past elections today and I thought I'd have a little fun. So I plugged in Obama and McCain's percentages from the Atlas (52.75% and 45.82%, respectively) and had Excel forecast the percentages for each candidate based on those trendlines.
A map using the trendlines from the last 25 elections (1908-2004) would have produced the following results:
This map looks a lot like FDR's victories in 1940 and 1944, not surprising given that his margins over Willkie and Dewey were similar to Obama's over McCain.
Using the trendline from the last 15 elections (1948-2004), yields this strange hybrid:
Using ten elections (1968-2004), Texas slips out of the Democratic grip, but Alabama and Mississippi make a comeback:
Using only the last five elections (1988-2004) produces the forecast that most accurately reflects the actual results, but the percentages are often wildly off (MA >70%, anyone?) and some states are just plain wrong - the trendline insists that poor West Virginia should still be Democratic, for instance.