Democracy had enemies before the founding of the Republic. Our founders warned us that it would require constant maintenance: "a republic, if you can keep it," warned Franklin.

Washington cautioned us that political parties would allow unprincipled men to subvert the power of the people.

Jefferson highlighted the criticality of public education: "If a nation expects to be ignorant and free, in a state of civilization, it expects what never was and never will be."

For Adams, it was the willingness of citizens to sacrifice their private interests for the sake of the community. He cautioned against purely self-interested rugged individualism, now a fake American ideal.

All of these have eroded from a combination of assault and neglect. This problem is asymmetric: those who assault democracy have more to gain than those who defend it (e.g. by looting it, or getting compensated by a foreign power, etc.)

In 1971, 2 months after Lewis Powell argued businesses use their political power to aggressively influence the law, Regan brought him on as a Supreme Court Justice. It was much more efficient to buy a justice for life. He helped set the stage for First Amendment protection of corporate speech, and Citizens United; ultimately legalizing the ability to secretly give a political candidate money.

The rot is really, really deep.

See also "boiling frogs".

But then I'm replying to @mr_toad so you probably knew that already.