re: #485 LGoPs

I think that is because the media has for years used the term to describe people of a conservative bent. They interchange it with far right, right wing and extreme.
What I think makes that attempt at branding particularly galling is that they never use the same branding for liberals. I think this is what leads to what you are puzzled about.

It might also be because there was a campaign right after the DHS report of people putting buttons on websites “Proud to be a Right-Wing Extremist”.