Disinformation, lies, has been around since humans have speech. That is not the problem.
All messages need a sender and a receiver. The readiness of Americans to receive and accept lies, like they want to be fooled, was the problem.
It could be that they didn’t know those were lies, and was fooled. That means their ability to tell lies from facts is the problem. There may be ways to fix it.
Or, they know these are lies and chose to believe lies. That’s hopeless