How did we get here? OR

How to deform a more Perfect Union, Establish Injustice, Ensure Domestic Riots, Provide for the Uncommon Defense, Demote the General Welfare, and Secure the Blessings of Liberty to 'ourselves' and our prosperity, to Ordain and Establish our own Hedgemony Constitution for the rich in America...

I will only go back to the time of my own first hand experience although the historic roots can go back to ancient times.
In 1958 the John Birch Society put on a suit and tie and represented a new image for the conservative right which had formerly been KKK values. In 1971 a guy named Powell created a memo for the Republican Party that outlined the long term steps needed to gain power forever.
It included things they called think tanks and quickly outnumbered Democratic think tanks 100 to 1. Powell also made strategies to undo the New Deal and change education to shape young minds. By calling government big and evil the cracks became wider to elect big government corruptors. The only thing that trickled down was meanness.

Changing definitions and the narrative was crucial. For example, journalism was based on the premise of objectivity and reason to reveal the truth. Republicans changed that from objectivity to 'balance' so if 99% believed in climate science the 1 percent deniers have an equal voice due to 'balance'. This strategy was most apparent in the Bush Jr. years. Also, vote tampering with computers was introduced and using the Court to decide elections.

THE DEATH OF THE FAIRNESS DOCTRINE
The news had always been required to be a public service in the public interest but that was stopped by Reagan. New talk radio was now sanctioned to become pure demagoguery rife with racism.

Enter the Internet and later the ultimate King of Mean...
and we are here.