[buckalfa]

"The coup happened on Usurpation Day, January 20, 2009."

I would use the date October 26, 2001. The date the Patriot Act was signed into law. I know surreptitious electronic surveillance existed before that date, but the passage of the act codified such surveillance making the spook agencies more vulnerable to political abuse.

[Lurkinanloomin]

That was when the Deep State achieved control.
Usurpation Day is when we officially left the Constitution behind.