Mencius Moldbug isn't the only conservative who's fallen for rhe idea that history has always moved left. It looks like Rep. Michele Bachmann (seen via Dispatches from the Culture Wars) is another one:
“Progressive” income tax rates were far higher in the 1950s than today.
Moving to taxes, Bachmann said that for some Americans, the ratio of tax payments to earned income can reach 50 percent -- compared to 5 percent in 1950.
On the other hand, that does not fit the standard left-wing dogma that history always moves left. Since Rep. Bachmann (R-idiculous) has apparently accepted that dogma, she believes that tax rates must have increased. (In case you're wondering, they haven't.)
ObSF: The Demolished Man by Alfred Bester, published in the 1950s, in which one of the characters was highly resentful of the confiscatory taxes levied on upper-income telepaths. It was another example of an attempted look at the future that soon became recognizable as a period piece.