What you describe is the winding-down days of communism, during it's hayday the arrests and torture didn't happen in the middle of the night, but in broad daylight, to cheering crowds. This phenomenon, not limited to communist states, works as follows:

The official line is not that everybody is happy and everything is perfect, but that everything would be perfect if it wasn't for the rightists/heretics/sexists/racists/etc. (depending on the society). The insidious thing about this is that anybody who has a different opinion and debates it can be charged with rightism, and is in fact guilty by definition. Heck anyone arrested, even if he wasn't originally a rightist has almost no way to defend himself without making the charge true. The only chance he has is demonstrating his loyalty by being as fanatical as possible at the next rally.