Why can't we vote twice?
You assumption of sheer ignorance ignores the problem of large numbers. A cooperative unit cannot grow beyond the size where the nice strategy of tit-for-tat with forgiveness no longer dominates in an iterated series of prisoners' dilemma (PD) of indefinite length. As soon as it does the incentives for defection split the cooperative unit into at least two smaller cooperative units, both of which, then, will be guided by the dominate strategy of tit-for-tat with forgiveness (with each other and all other smaller cooperative units).
A large cooperative unit will use force to try to use force to prevent defection which, of course, is itself a defection (how can it be a cooperative unit if it forces cooperation?). It will also use force to prevent the formation of cooperating units that do not cooperate with it. Both these defections lead to a lose-lose string of games, which is why the "forgiveness" part of tit-for-tat with forgiveness is so important; it breaks the string of defections. It also increases the incentives of smaller cooperative units to cooperate with each other (even if they have to do it clandestinely).
The effectiveness of the force used is related to geography. Obviously, physical force is useless against someone you can not reach physically. As a large cooperative unit transforms to a defective unit with force, the smaller cooperative units which defect tend to move away; therefore, one of the last death throws of a unit which has adopted the defective strategy of force is travel restrictions. Once travel restrictions have been imposed, it becomes clear to cooperative units of all sizes (down to the individual) that the PD series of indefinite length has or will soon end.
As the dominate strategy for the Nth PD game is defect/defect, it is also the dominate strategy for N-1, and thus for N-2, and so on. Therefore, the lifespan of a defective unit with force is inversely proportional to the degree of travel restrictions imposed and its ability to enforce those travel restrictions.
All of that boils down to the repeated observation throughout history that the rise of cooperative units (government or otherwise) which cease to be cooperative and start being forceful are inevitable but unstable - their days are numbered at the moment they employ the defective strategy of force.