NOTE: I'll admit that this whole timeline is implausible and ASB. No need to tell me. I know that.
POD: The 501st Legion (the Fan Group) nominates George Lucas for President in 1984 and he wins.
Late 1983: Some members of the 501st Legion decide to turn the Legion into a political party as a joke.
May 1984: Indiana Jones and the Temple of Doom is released.
November 1984: The 501st Legion (known informally as the Galactic Party) nominates George Lucas for President and John Williams for Vice President. On the ballot, all the Galactics vote for the Lucas/Williams ticket. In the electoral college, the Lucas/Williams ticket barely wins it. The majority of the country is in an upset and the Galactic Party is surprised. The Reagan Administaration agrees to give Lucas the Presidency if he accepts his victory. Lucas agrees to take the presidency. (ASB)
Later in November: Caravan of Courage is released.
January 1984: Lucas is inaguarated with the Army Band playing the Imperial March (ASB). For his Cabinet, he chooses from Star Wars actors and Democratic politicians.
1986: President Lucas gives the Imperial Soviet speech, in which he compares the tyranny of the Soviet Union to that of the Empire in the Star Wars trilogy.
1985-1989: George Lucas leaves most Presidential duties to Secretary of State William J. Clinton so he can continue his filmography.
1988: George Lucas decides not to run for President. Instead, he suggests Irvin Kershner (the director of Episode V) for President and David Prowse for Vice President. The Kershner/Prowse ticket becomes the Galactic nomination. The ticket wins.
1989: Kershner is inaguarated. Indiana Jones and the Last Crusade released.
1992: David Prowse and James Earl Jones becomes the Galactic Party's nominee for the Election. The Americans, satisfied with the Star Wars rule (mostly a center-left version of the Reagan/Bush presidencies) elect the Galactics again.
1996: James Earl Jones and Harrison Ford are the Galactic nominees. They win. Because of the "Star Wars" rule, the US and USSR do not ease tensions and at this time, the USSR still exists, as does East and West Germany.
2000: The Galactic Party ceases to end and merges into the Democratic Party. Al Gore loses to George Bush.