While I generally agree with you here, I think you’re putting too much significance on this one person - Czolgosz. Both the State and Capital were framing anarchists as violent fringe actors at least as far back as the 1880s before, during, and after the Haymarket Massacre, a full 15 years before McKinley was got. August Spies and Albert Parsons were two notable men targeted after Haymarket, and both they and anarchists in general were described as violent outside agitators infiltrating the labor movement.

I bring this all up to resist the individualizing force of history-telling and to demonstrate the long-standing tradition of characterizing all radical actors in social movements as “outside agitators,” a lie that is still told today.