On one hand, how could a self-described “believer in freedom” like Marcuse not offer up a critique of the Soviet Union after the invasions of Poland and Hungary in 1956, the Gulag, the purges, the class “liquidations”, the secret police, etc? On the other hand, how could someone fairly loyal to Marx (as Marcuse was), fail to see many good things in the Soviet system (as the Guardian's Seumas Milne still does to this very day)?
Although Herbert Marcuse rejected much about the Soviet Union and, to a lesser extent, about Marxism, he didn't by any means way reject Marxism/communism completely. In fact he had a similar position on the Soviet Union (though not on Marxism) as Trotskyists do in his day and in our own. And, of course, Trotsky's criticisms of the Soviet Union and Stalin predated Marcuse's main critique by some 30 years.
In his book, Soviet Marxism (1958), Marcuse explicitly argues that Marxism didn't of necessity lead to Soviet totalitarianism. Indeed it was partly because he didn't break with Marxism completely that he was allowed to break, to some extent, with the Soviet Union. If he had broken with the Soviet Union as well as with Marxism, he simply wouldn't have been listened to by his fellow Leftists. As it was, he was one of the first Marxist intellectuals - in the US at least - who spoke out against the USSR. Yet that was still some five years after the death of Stalin. (Or, at the very least, his book, Soviet Marxism, was written five years after Stalin's death.)
Yet the very fact that this book is called Soviet Marxism shows us that Marcuse still believed that the Soviet system was a form of Marxism; not a “deviation” (as Marxists put it) from Marxism.
It was partly because Marcuse believed that the Soviet Union still contained, as it were, some good or true Marxism that he thought it was still capable of reforming itself. Marcuse believed that this true (or good) Marxism could or would win through in the end and get rid of the bad Marxism (i.e., Stalinism).
To put this another way: Marcuse believed, as many Marxists still do, that there's a large disconnection between (correct/sacred) Marxist theory and the Soviet implementation of Marxism.
As a consequence of this, it was bound to be the case that Marcuse would disagree with those who believed that the Soviet regime was a bureaucratic system which was incapable of reform. However, such people shouldn’t have believed that the Soviet system was necessarily incapable of reform. What is misguided was Marcuse's view that it could reform because there was a kernel of pure - or proper - Marxism within it. In other words, although on the one hand there is never any political or structural necessity (i.e., endless stability and sustainability) when it comes to totalitarian regimes (as the neo-cons also believed about such states), Marcuse's own belief that proper - or true - Marxism would eventually save the Soviet Union was also a bad (Marxist) idea.
Michele Foucault, for one, was sceptical about this Marxist theory-Soviet practice dichotomy. In Madness and Civilisation he wrote:
“In the Gulag one sees not the consequences of any unhappy mistake, but the effects of the ‘truest’ of theories [i.e., Marxism] in the political order.”
To repeat: Marcuse believed that Marxism had been somewhat perverted by the Soviet system. Clearly he didn't believe that Marxism itself was perverted. And, as a consequence, Marcuse argued (in the late 1950s) that the Soviet Union could reform itself and yet still remain loyal to Marxism/communism. In other words, he didn't believe that the secret police, censorship, centralised leadership, Gulag, purges, class “liquidations”, anti-liberalism, etc. were essential to Marxism/communism and also required to sustain it.
In response to Khrushchev's moves, Marcuse wrote:
“With respect to internal Soviet developments, this means at present continuation of 'collective leadership', decline in power of the secret police, decentralization, legal reforms, relaxation of censorship, liberalization in cultural life.” (1958, p.174, Soviet Marxism)
Despite these words, it took around three decades after writing the above for glasnost and perestroika - under Gorbachev - to come to the Soviet Union. And, indeed, to the extent that collective leadership, decentralisation, legal reforms and the liberalisation of cultural life increased, and the power of the secret police and Gulag declined, so Marxism/communism itself declined. Surely this should have shown Marcuse that there is indeed an essential connection - at least in the Soviet Union's case - between Marxism/communism and totalitarianism. Nonetheless, Marcuse still believed that Marxism/communism could run free of totalitarianism. It never never has.
Although Marcuse embraced the Marxist view that the working class couldn't think for itself (unless, of course, liberated by middle-class Marxist theoreticians), he nonetheless did reject various sacred and classical Marxist catechisms:
i) He questioned the fact that the working class is automatically a “revolutionary class” (or would become revolutionary if Marxist prophesies finally came to pass). ii) He questioned - though didn't necessarily reject or deny - the “inevitability” of a capitalist crisis which had been prophesised since the 1850s. (Though a distinction can be made here - and had to be made by Marxists - between a capitalist crisis, with the indefinite article, and the “final capitalist crisis”, as prophesised by Marx.)
Marcuse firstly rejected these things, at least in print, roundabout 1958. However, Marxists had rejected the necessarily revolutionary nature of the working class - as well as the "inevitability of a capitalist crisis" - as early as the 1890s; as was the case with theorists like Eduard Bernstein and others. So in these respects, Marcuse wasn't saying anything new or original.
Marcuse did indeed update the general Marxist package in the late 1950s and 1960s. That's not a surprise. That Marxist package had been updated by every generation since Marx himself. Indeed Marxists are still updating Marxism.
One such update (or “deviation”), for example, was Antonio Gramsci's advice that Marxists/Leftists should “take over the institutions” and by doing so turn Marx's base-superstructure model on its head. A more recent updating is the completely non-critical attitude Marxists have suddenly adopted towards religion: or, more accurately, towards Islam (1).
1) To put that another way. Marxists have completely abandoned their traditionally virulent critique of religion in response to the rise of Muslim demographics in the West. In classical (Leftist) racist style, Marxists have become more “sophisticated” about religion quite simply because many religious people in the West now have brown, rather than white, skins.