I love elections for their ability to change the game's landscape sometimes drastically. Not tying the offices to the politics career is a good call! Business works well for aspiring politicians, as does Law, but also Conservationist for their ability to propose global policies. How are you handling Conservationists in your game? Do you let them use their ability or do they need to forge contacts or acquire certain merits first?
I used to have a standardized system where each political party was represented by a GT club. Each club had the same rules and used the same public lot for vote aquisition. That was done by a 24 hour club outing. Before the election, each party had to propose one venue to build and one gameplay rule that I had to follow until the next election. Naturally I only chose venues and laws that I was willing to play with.
Nowadays I have an Election Day holiday with the customs "Attend holiday service" (go voting), Brawl and Watch TV. The actual elections are more story driven, but often contain scoring of some kind. Although my game is centered around Detroit and Windsor with their suburbs, there is no limit to the position a played sim can attain. Currently I have a played sim as US president and a played sim as Mayor of Detroit, but the Governor of Michigan is an npc. On the Canadian side no office is held by a played sim since Jacques Villareal passed away.