There is polarization, that spreads out voters to all extremes.
I think it would be nice to have events or stuff, that will try to push your country into one of extremes.
Pressure Groups sounds like perfect place for it.
There are already promises and suggested policies that opposition/coalition or ministers want to push.
There would be policies, that increase chance of voters joining pressure group.
So there could be recurring policy suggestions from pressure groups, that increase happiness and/or membership of following groups:
Wealthy, Capitalists, Conservatives, Religious, Patriots, Poor, Socialists, Liberals, Environmentalists, Minorities, and any other voters that have pressure groups.
It doesn’t have to be pressure groups themselves - it could be separate thing like Lobbing Groups, that suggest and or demand new policies, or changes to existing policies.
Lobbing group power could be influenced by pressure/terrorist groups, events, dilemmas, situations, simulations and policies.