It does have one meaning, which is "the others". It's the old fascist principle of us vs. them. But rather than arbitrarily drawing the line at nation borders, religion, genetics etc., they've chosen a new frontier against progressive ideas.
I imagine, it has gained popularity, because with the advent of the internet, we've started generating more progressive ideas at a staggering rate. And for those who can't keep up with that, it's attractive to proclaim all of that stupid, because actually considering it and re-evaluating one's beliefs, that takes effort.