It's fairly easy to a smear campaign someone that does not fit into your narative.

All you have to do is put some labels on him, take things of out context, attribute things not said or done to the said person, and pretend to debunk him.

This way you never have to make the counterargument to the argument made by that person. You just dismiss him in whole.

I don't know if that's the case here, but considering the name-calling from the start, the typical labeling (racist, homophobe, islamophobe, Nazi, RT-shill), I'd say it fits.