Personally, I wasn't really a fan of how ideology was treated mainly as a way to simulate the diplomatic tensions of the cold war and/or WW2. I would much rather have ideologies expressed as some form of simplified equivalent to the social class system seen in various Paradox grand strategy titles, most notably the one in Victoria 3.
The way I would depict ideology as a mechanic, would be to have each citizen subscribe to one of five different ideological factions (one for each corner of the political compass plus the dead centre of it), based on where they're stationed and what other citizens they're neighbouring. On top of that, each social policy would have a positive/negative modifier associated with at least one ideological faction each, with said effect's strength determined by the respective faction's prominence within the civilization. Perhaps the different factions should also have pronounced attitudes towards the different victory conditions as well.
I don't know, I feel that when making a game like Civilization, it's generally better to draw inspiration from sociology and anthropology rather than from history. History is about what did happen, and Civilization is a game about what can happen