The single most important thing the populace must be kept distracted from is the awareness that just by sheer numbers they have the power to subvert any and all power structure when they work together. This is done primarily in two ways: exemplary persecution and divide et impera.
3/
Exemplary persecution means taking a small number of exponents (possibly even just one) of any movement that is manifestly getting traction among the populace, and “throw the book at them”, as the saying goes. This may be on made-up charges, but in most cases it's actually possible to find thing these characters are really guilty of, and just apply the harshest possible sentence (and then some).
4/
This is sometimes sufficient to kill momentum of specific organizations or movements, but consistently fails at killing the idea behind it, making it just a matter of time before new figures emerge to drive it forward. This is were divide et impera comes in handy. It's very rare for all enemies to power to share the same grievances, or more in general to belong to a single uniform group, so the best bet for power is to ensure that these groups remain isolated from each other.
5/
This was (is?) often done by force, for example by preventing people from a conquered region to contact people from other conquered regions, or by actively pitting groups against each other by giving them police power (the British Empire refined this strategy and used it extensively everywhere, most famously in India and Palestine). But why waste your resources on that when you can just fuel people's innate tendency to separate in-group and out-group sentiments?
6/
Oblomov