"Democracy" is a tricky word - it means different things to many people. I used the term in a "minimalist" sense - to denote a system based on a constitutional law, elected government, and broad (if not truly universal) suffrage - as opposed to, say, monarchies or dictatorships. In that sense, pre-fascist Germany and Italy were democracies, but even their fascist regimes could claim, to a point, that they were demorcatically elected.
But the point I am trying to make is that a modern industrialized state which implies, inter alia, relatively high urbanization, industrialization and weak if not absent fedual-like institutions (such as hereditary monarchy, strong land-owning oligarchies, and dominance of plantation-like economy) has a very slim chance of experiencing a "communist" revolution as we know it (i.e. along the Russian or Chinese lines), because such revolutions were a product of social forces that are relativeky weak in such societies (i.e. peasants and agrarian workers). The forms of class struggle in such societies are very much different and involve, inter alia, labor organizations, parliamentary politics, and state social welfare policies (cf. Sweden where the worker-peasant alliance was ablse to install "socialist" social welfare policies and partial nationalization of the economy through parliamentary means). The only "revoution" that has so far succeeded in such societies is fascism - which is instigated and bankrolled by oligarchies to protect its privileges against parliamentary advances of the working class movement.
Keep it in mind that the working class strength is in its numbers and that gives them tremendous power in the elections. That power is usually diluted by bourgeois culture and propaganda, and if that fails, by a fascist coup. But the bottom line is that even if a minimally democratic system, the working class can succeed by the parliamentary means. It is the oligarchy that needs extra-parliamentary means, such as cronies in the Supreme Court or a fascist coup, to hold to power.
Wojtek