The first thing Bookman does is describe this as "unacceptable behavior." Which is exactly what it is. One of the most effective ways to discourage it is to demonstrate disapproval. Maybe we'd get somewhere if more folks stopped rationalizing the bad behavior of people they agree with politically.
In California, a national political personality was giving a talk. Because this personality helped develop and implement controversial policies certain Americans didn't agree with, protestors disrupted the meeting and said he "lied" and "destroyed the country." Unacceptable behavior.
Where have I seen this before? Oh, yeah. When we last saw unacceptable behavior.
Thanks for the Latin, DADvocate. Looks like it will come in handy.