Imagine that you are a group of rich and powerful people eager to be still richer and more powerful. But you live in a democratic society that gives each citizen an equal vote and thus sets sets limit on how much power you can amass. So you decide to steal the people's democracy.
For starters, you would work to prevent the people from working together. As long as they can unite for common purposes, they can prevent you from gaining power over them.
Sowing hatred among them will work well to stop them from coming together. You don't have to reach all the people--half will do. If one half hates and distrusts the other half deeply enough, that will suffice to ensure that the people will be unable to cooperate to achieve goals they have in common.
To sow this enmity, you will need a media system. Through that system, you continually tell the people who listen to you how terrible the others are. They are not your fellow citizens with a somewhat different point of view, you tell them. They are the enemy. They don't love the nation; they have betrayed it. They want to steal your liberties and set up a tyranny over you.
This challenge can be met, however, by training the audience to listen to no one but you.
You teach them to disregard anything they hear from members of the political party opposing the one you have chosen as your instrument. You teach them to have contempt for the scientific and scholarly disciplines that pursue truth for its own sake. You teach them that all the media you don't control are tools of the enemy. And you teach them to disrespect other nations whose judgments will likely cast what you're doing in a harsh light.
It also helps, in selling lies, to continually feed people's fears because fear makes it more difficult for people to think rationally.
Those steps are important but not enough. If the system you're trying to take over is based on "one person, one vote," the people can still take control. As part of your strategy, therefore, you will work to take power in the election process away from the vote (where citizens are equal) by increasing the power of money (whose unequal distribution favors you).
The more that wealth is able to buy elections, the more you can pick the winners, and the readier the winners will be to serve you and not the people. If there are laws that limit the role of money in elections, you'll need to work behind the scenes for years to place judges who will sweep those laws away.
Even that is not a complete strategy for maximizing your power.
To weaken government as a potential check on your power, you will use your propaganda apparatus to persuade those citizens who get their view of the world from you to distrust government, to believe that the biggest threat to their liberties is not from your stealing their government but from government being "too big."
In these ways, you can come to dominate and exploit what had been a free people.