Though there is disagreement on what these are, pretty much everyone agrees that lessons can be learned from comparing the conditions which brought about so-called “classical” fascism in Germany and Italy and what we are confronting now.
Among those is Noam Chomsky who has recently argued that there is a indeed a Weimar analogy to be made.
But, according to Chomsky, before making it, it is first necessary to understand certain basic facts. Among these is that
“Allowing free speech to Nazis had nothing to do with their rise to power, legally.”