1980: Jimmy Carter destroys Ronald Reagan in the debates and pulls off a decent win:
The economy goes exactly as it did in real life: faltering in 1982 gives Republican control of the Senate, but by the time 1984 rolls around, the economy is in good shape.
Ted Kennedy, who did not run in 1980 in this world, runs in '84 and wins the nomination. He chooses as his running mate Geraldine Ferarro. George Bush gets the GOP nomination and chooses Senate Majority Leader Howard Barker as his running mate.
What happens? Elaborate with maps.