I’m pretty sure maps #2 and #3 are swapped. Wyoming, for example, is much smaller in map #3 than #2, while New Hampshire and Vermont are closer in size in #2 than #3.
These ones don’t really look all that different from ones of 2008, but the difference between those two and the 2004 one is pretty significant. Interestingly if you compared 2000’s map with screen 6 of the 2012 maps what stands out is how much less purple we are since that Bush v Gore election. (And become that much less purple by 2004.)
Look for example middle of the south from Northeastern Texas eastwards. In 2000 that is almost all purple with a little red and a little blue; 2012 hardly any purple counties, red until you hit that North South line of blue.
Here’s a gif that shows the map changing from 1960 through the 2008 results. Third parties make the colors a bit more varied. I love to see a similar gif of the cartogram!
Note what these maps make clear: The geographical-political divide in America today is not Red States v. Blue States, nor North vs. South, nor East vs. West, nor Coasts vs. Flyover; it is Countryside (Pub) vs. City (Dem). The maps shade from red for the least-populous counties, through purple for the suburbs/exurbs, to blue for the dense urban areas.
And whenever a conflict comes down to Countryside vs. City, the Countryside usually loses and usually deserves to lose.