Progressive violence

The news today that a “Gay Marriage” advocate attacked the Family Research Council in Washington, D.C., shooting a security guard in the process, got me to pondering this question: has any act of political violence in the U.S. ever been associated with conservatives or Republicans?

On the Democrat /Progressive side, of course, we have violence against blacks, babies, Tea Party rallies and Republicans; political assassinations; lynch mobs; KKK; Nazi party; Communist party; Black Panthers, Weathermen, enviro-terrorism; animal rights terrorism; campus violence against Jews; Occupy Wall Street…

So, again, I pose the question…is there any political violence in the U.S. – anytime and any place – that can be attributed to Republicans and/or conservatives?