Ideology rethought

The new Ideologies are pretty awesome. However, I get the feeling they would be better treated as something to be developed, a sort of late game religion if you will. Instead of instantly having an entire nation adopt a policy how about a city by city basis. Keep the public opinion meter and use this to increase the support of your chosen Ideology. Great Politicians could be introduced, very similar to GPs in eliminating differing Ideologies and spamming your own. They could also create a Party Headquarters [?] to dramatically increase a cities loyalty to the cause. This would make the spread of Ideologies more realistic and easier to manipulate your friends and neighbors.

What if I capture a Great Politician from another civ who's ideology is different from mine? Could I use him to introduce bi-partisanship into my government? It might be difficult to get anything done then. I also wouldn't like having to allocate some of my income toward political campaigning. I actually like the idea of having developing ideologies, but only if we can keep politicians out of it.