Isn't that just Dixiecrats/Dixie Dems then? AKA former Confederates.
I use it because of the extremism of the MAGA crowd, not the conservatism. Not like Horseshoe Theory, but that extremists on the leftist side could have fallen down the MAGA rabbit hole instead under different life circumstances, and that they can show similar behaviors in "purity test" attitudes, etc. Not that they're terrorists like the MAGA crowd, but that they should probably log off and touch grass once and a while.
Not something to be used wildly, but towards those who show 4chan-like behavior.