The “right wing propaganda” to them is literally anything that is negative about liberals.

Their conception of “left” is that liberal = as far left as you get. Anything negative about liberals is therefore right wing.

They see “I do not like libs” and go to “this is right wing” in their headspace because they know literally nothing other than democrat vs republican. They don’t even understand that those are just two halves of liberalism. If you explained that the fascists in Japan are the liberal party their heads explode.