There are three possibilities:
#1 It is possible that this is a planted story by the government to see how much indignation will be displayed by the public as well as the conservative politicians.
#2 It is a plant to see who is going to threaten violence. Be careful with dumb “I’ll ....whatever”, unless you want the FBI giving you the treatment of a swat team breaking down your door at daylight.
#3 They are really dumb enough to do it.
Republicans won’t say a word.
I'd NEVER threaten violence. I am, at heart, a pacifist.
I might observe that OTHERS would threaten violence, but that is a mere observation.