Do you guys remember that NYT editorial a few years ago that raked the far-left extremist greens over the coals for their violent tactics? Or maybe you remember when Paul Krugman excoriated open Marxists for their economic idiocy. Perhaps you recall when CNN did a roundtable on significant problem of the embarrassing scientific illiteracy of the average Congressional Black Caucus member.
Of course you don't, because none of that ever happened.
One of the great strengths of the left is their clear understanding of who their true enemies are. The more moderate leftists know they need the drive, energy, and passion of the radicals. The radicals know that they can't obtain any power at all without the moderates.
The right does not understand this. Conservatives of all stripes continually fall into the trap of denouncing anyone to the right of where they're comfortable. The GOP establishment denounces the conservatives. The mainstream conservatives denounce the Tea Party. Tea Partiers denounce libertarians. Libertarians denounce social conservatives. Race realists are denounced by everyone. Once they're aware of the alt-right, we'll be denounced, too.
When I talk about "denouncing," I don't mean calling someone out for being a worthless sack of crap. I mean when you publicly berate someone on the right for being an "extremist" or whatever for the express purpose of being more socially acceptable. The left plays this game with Republicans via the media. They hold out the false promise, "If you just denounce these bigots to the right of you, we'll treat you much more kindly on our TV shows." This is, of course, a lie. John McCain and Mitt Romney pandered to the left-wing media nonstop during the primaries, but were treated like The Second Coming of Hitler (implying that would be bad) once the election began.
The whole point of denunciation is to signal your moral acceptability to the other side. The left never does it because the leftists don't care about being accepted by the right. The problem with this sort of signaling is that it grants the premise that the left is the final authority on good and evil. This keeps the right fractured internally and always on defense. The right must always attack, never defend.