An interesting observation after traditional Christmas arguments with my right--wing relatives in Poland:
Alt-right is now talking 100% postmodernism.
History made full circle: half-century ago it was mostly far left who ranted about "gender aspect of mathematics" and "science as a social construct", basically denying humans ability to objectively describe reality.
These tools were initially forged by Marx to facilitate his wishful thinking about how societies operate that science did not support.
In 20th century far-left faced the same challenge and picked the same tools as they knew them well due to ideological compatibility and general inspiration by Marx.
Today the same Marx-inspired tools are being picked up by alt-right generation that talks about "evils of cultural Marxism" (a bullshit term on its own).
Sokal Affair was LOL, this is LOL squared.
This sounds like a good explanation of the generic mechanism but what raised my eyebrows was that the relative I talked to was almost literally quoting the arguments you could before only in works of postmodernist philosophers such as Derrida - far fetching statements about relativity of science and inability to describe reality objectively. He used it specifically to reject easily observed phenomena such as CO2 concentration in atmosphere, so you get where that was going :)