I'd guess he was not.
It is a shame that a prolific author with such a long and distinguished bibliography should be associated with only one work because it is controversial. But that is how the world works...
Part of the genius of the work (mostly lost in all of the Hollywood attempts to make it, even the original in which Nabokov himself participated in writing the screenplay) is the portrayal of disgusting evil in the guise of a more-or-less otherwise ordinary person, not some dumb@ss comic book character caricature.
My favorite of several political quotes from Nabokov, a fantasticly understated putdown of an academic "fellow traveler:" 'Yes, he was one of those professors who somehow believed that only American nuclear tests produced fallout.'
The book is a brilliant satire - of pc avant le lettre - and about obsession. Nabokov was that great rarity, an intellectual and superb artist who was also a conservative. He led a heroic life in opposition to the Left, and deserves sainthood.