Even in its newly metastasized state, the left has always had a moral trump card: fairness. For example, libertarians are correct when they argue that welfare is economically inefficient, but the left's response is that markets are intrinsically unfair to people who aren't born in the right place, at the right time, to the right people. Conservatives are likewise correct when they argue that it's silly for everyone to pay the same health insurance rate, but the left's response is that it's unfair to people with congenital diseases. And should you bring up the specter of immigration, the leftist will remind you how terribly unfair that is to people who just happened to have been born in the wrong country.
The left is correct, of course. All that rightists of any stripe propose is indeed unfair. Our lame attempts to prove it is fair always fail, accusing the liberals of being more unfair always backfires, and trying to argue that efficiency or liberty might trump fairness always falls flat. Because we're not fair. Of course, the world isn't fair, which is why we have a monopoly on realists and the left has a lock on utopian autoklaniaphiles.
But there is a common thread among the fruits of the spirit of Dildolech---bankrupt states, blown-out urban cores, demographic displacement, and sub-replacement birth rates---and that is civilizational death. Fairness doesn't matter when you're dead.
The right's moral imperative is survival. This is what all right-wing political ideologies, from libertarian to conservative to alt-right and beyond, strive for. The left's ideals are evil because they are suicidal. Leftism is a failure on its own terms because the only future for a society under left-wing hegemony is dying. Look at Detroit, once a bastion of white progressivism! It is now a skeletal ruin being picked over by illiterate savages who know nothing of the city's former greatness. That is America's future under the left, not the Modern Family fantasy of peaceful, bourgeois, mixed-race homosexuals.
Give the left no quarter, because Progress is a suicide pact. If we follow it, we die. And what of "fairness"? The answer is simple. Fairness is stupid. It's what little children believe in, along with the Tooth Fairy and invisible friends, and no one who believes in it deserves to be taken seriously. Progressivism is a civilizational suicide pact. Survival, not fairness, is the common principle we appeal to.