The Russians fell into authoritarism because the union fell, and with it, the last vestiges of consultative process that the Russian people had with their politicians.Now that was some delusional crap if I ever read it.
The reasons for Russia falling back into an authoritarian stance after the 1990s were two. 1. The massive socioeconomic chaos after the US sponsored privatizations, which caused social conditions so severe they were opposed by the Russian Duma, and then US puppet Yeltsin was forced to attack the parliament building and impose martial law to ram the changes through thus setting the precedent. 2. The US' continuous erosion of Russia's security environment, by annexing former republics of the Soviet Union into NATO, and sponsoring terrorism inside Russia including in Chechnya.
The economic conditions in Russia were also made much, much, worse because the US insisted on putting the whole burden of paying the Soviet Union's debts on the Russian government. Compare this with Poland which got its debts forgiven.
America demanded that Russians must adopt the full western political system and elite dominate politics. The modern Russia is no longer loyal to USA, but the Russian elites find the authoritarism useful, so they have kept that aspect of western thinking. Nowadays, Russians have no more say in government affairs than the average Polish, Greek or German citizen have in EU affairs.