That's how society progresses though. Before 1865, slavery was mainstream and abolitionists were weird radical crazies. Before 1965, "Jim Crow" laws that said non-whites had to use different bathrooms and drinking fountains were mainstream, and people who opposed them were seen as unreasonable.
Eugenics as in forcible sterilization of the “unfit” was similarly Progressive back in the early 20th.
I'm not sure either of those are particularly progressive -- the current president seems to be a fan of tariffs, a form of planned economy popular in the 19th century (and condemned by most economists since, who favor free trade). And child brides are a common feature of many right-wing religious groups, argued on the grounds that that people (particularly female) traditionally married in their teen years.
And back in the 1960s a planned economy was normal and reasonable, and many progressives openly called for normalisation of sex with teenagers. Sometimes shifts in attitudes are progress. Sometimes they're just a random walk. Sometimes the left is right, sometimes the right is.