There are always remnants that exist. For instance, on Heijian Star in various old kingdoms, there are diehards of the Loyalist Party, remnants of the old gangs of Korolya, former bureaucrats, remnants of the Fatches Family, and former business owners of Flying Wing Star who were nationalized... as well as their sympathizers and supporters, have always existed.
Some were beaten by the iron fist but not thoroughly, while others pretend to get on board with the Federation but secretly continue to aid those remnants.
These guys, of course, don't dare to act openly.
If they do, they'd be signing their death warrants. Under the strong, unified, and tight rule of the Federation, with powerful military forces and the widespread trust of the populace, direct rebellion and confrontation would be like an egg striking a rock.
However, this does not mean that their hatred and the will to resist has been completely extinguished.
