Project Megiddo lies in the background of this. The infiltration and use of "right-wing" front groups is a revival of the FBI's Cold War COINTELPRO programs and is part of a bigger project that encompassed the following groupings as of 2017 (per a Virginia Department of Criminal Justice Services course titled "Introduction to Domestic Extremism and Hate Groups"):
Animal Liberation Front (ALF)
PETA
Earth Liberation Front (ELF)
Black Hebrew Israelites (BHI)/Black Separatists (New Black Panther Party) aka Black Identity Extremism
Anarchists
Militia Groups/Sovereign Ideology
White Supremacists/Racist Skinheads
Internet Radicalization