Part of the problem is that the left has erased all evidence of the failures of progressive politics (and in many cases the right has let them do so). When you just hear about the civil rights movement and marriage equality, it’s easy to assume that conservatives are just there to hold everyone back.
I’d offer three examples. First, “socialism.” Socialism failed dismally. One of the most colossal failures of a political idea in modern history. So progressives endeavored to replace “socialism” with “social democracy.” But “social democracy” as practiced in Europe approaches the problem from the complete opposite end. It abandons the socialist economic model and builds on a capitalist one. Put differently, it’s not “socialism with more democracy” it’s “capitalism with more democracy.” So progressives have turned social democracy—which is more than anything an affirmation of the success of capitalism, and an utter retreat from what progressives were pushing before—into a win for progressivism.
The second is the sexual revolution. At least in the United States, we have retrenched significantly on that front. Millennials start having sex later, and have fewer partners. “Affirmative consent” has replaced “free love.” The boundary-pushing on things like age have been pulled back hard. The #MeToo movement reaffirmed conservative truths: men cannot be trusted and society has a role to play helping women stave off unwanted and inappropriate advances. (Andrea Dworkin addresses this at length in Right Wing Women, though obviously long before #MeToo. In explaining why many women continue to support patriarchal systems, she notes that the sexual revolution stripped women of a lot of protections that those systems used to provide, with nothing to replace them. While Dworkin was obviously no conservative, she astutely recognized that the progressive tendency to throw out rules can easily end up overreaching. Many have lamented that the #MeToo movement is a return to a more Puritanical approach. There is a lot of truth to that.)
Third, eugenics. The history of support for eugenics in this country has been pretty much erased, even though the evils of Jim Crow get plenty of attention. That’s likely because many progressives backed eugenics. Woodrow Wilson, progressive champion, was a former New Jersey Governor and eugenicist who segregated the federal work force for the first time. He fired existing black federal employees (proving he wasn’t just a product of his time). Meanwhile, one of the strongest opponents of eugenics was the Catholic Church. In 1930, the Pope released an encyclical in which he condemned birth control, abortion, and eugenics as all being incompatible with the traditional Christian view of reproduction.