It comes from having a dominant ("hegemonic") discourse - basically the set of values, mores, opinions, etc. that are allowed to be aired in public. A consistent Overton window throughout the population, basically.
Periods in history like now (or the late-1920s/1930s, or the 1850s-1860s, or the mid-1600s) are ones where there is ambiguity in power structures. You have multiple competing ideologies, each of which thinks they are more powerful than the others. Society devolves into a state of anomie, where there's no point following the rules of society because there are multiple competing sets of rules for society.
The usual result is war, often widespread, because the multiple competing value systems cannot compromise and so resort to exterminating the opposing viewpoint to ensure their dominance. Then the victors write the histories, talk about their glorious victory and about how the rebels threatened society but the threat was waved off, and institute a new set of values that everyone in the society must live by. Then you can get accountability, because there is widespread agreement on the code of conduct and acceptable set of justifications for the populace at large to judge people by.
Periods in history like now (or the late-1920s/1930s, or the 1850s-1860s, or the mid-1600s) are ones where there is ambiguity in power structures. You have multiple competing ideologies, each of which thinks they are more powerful than the others. Society devolves into a state of anomie, where there's no point following the rules of society because there are multiple competing sets of rules for society.
The usual result is war, often widespread, because the multiple competing value systems cannot compromise and so resort to exterminating the opposing viewpoint to ensure their dominance. Then the victors write the histories, talk about their glorious victory and about how the rebels threatened society but the threat was waved off, and institute a new set of values that everyone in the society must live by. Then you can get accountability, because there is widespread agreement on the code of conduct and acceptable set of justifications for the populace at large to judge people by.