I occasionally make the point that after the Left invented post-modernism, the Right operationalised it and rolled it out as a coherent political-media-aesthetic package. If your politics depends on disagreeing with objective reality, and persuading people to vote against their interests, there is a huge opportunity in the realisation that it’s possible to have multiple competing truths. Setting the limits of debate, and controlling the language in which it is carried out, is a valid and proven strategy for power.
Similarly it’s not entirely bogus to link the collapse of the centre-left today to the collapse of the far left in the 90s (which in turn came about from the collapse of the USSR). Eurocommunists, as well as being useful idiots for the Kremlin, were crucially also outriders for the social democrats. The Trots may have been loathed by the moderates, and may have lost them numerous elections one way or another, but they also forced them to confront serious issues. Here’s hoping the pirates, the greens, and the non-party activists can fulfill the same purpose today.