... that the heckler was a plant. Why would the "Sieg Heil" screamer be so far back in the room near the cameras, where the heckler also happened to be? Seems fishy to me.
As for the people who physically assaulted the guy, well, those were real Trump supporters. It's just what they do.
It's funny that you discredit other things that were/are done at Trump rallies, but yet you accept that Trump supporters do physically assault protesters, when you say
"It's just what they do."
If you believe Trump supporters "physically assault" protesters, why would you question them screaming "Shoot him!" "Kick his ass," and "Light the motherf—-r on fire!" Actions (physically assaulting) are much more perceived as negative/bad attributes, than simply screaming derogatory words.
Some Trump supporters screaming "Sieg heil!" should not be a shock to you, as we know that white supremacists and neo-Nazi groups support much of what Trump says.
If you read the full article, there is another Trump supporting described as doing the following:
"He's a Muslim!" another man in a glittering black suit shouted as another protester was removed. "He's a Muslim!"Here again, this should not be a shocker that Trump supporters feel ill-will towards Muslims and other immigrants.
In conclusion:
No one was "planted" in the rally to say these things. There is nothing "fishy" about the things that were said and done at this Trump gathering.
All these things were done by "real Trump supporters," because in your great words ...
"It's just what they do."
