In the communist manifesto, Marx wrote:
We have seen above, that the first step in the revolution by the working class, is to raise the proletariat to the position of ruling class, to win the battle for democracy.
By "win the battle for democracy" Marx assumes that if the vote is extended to all classes, since the proletariat is numerically greater than the bourgeoisie and the nobility, that this would result in a proletariat government as soon as the consciousness of the proletariat had been raised. Indeed Engels wrote
the struggle for the general franchise, for democracy, [is] one of the first and most important tasks of the militant proletariat
However, in the Marxist view, the election of proletariat leaders can only be a step towards communism. The natural goal of a communist society is essentially anarchistic: a society in which the means of production and the levers of power are held in common. In which there would be be no government in a form that would be recognisable to one living in a Capitalist country. This requires a fundamental change of perspective: democracy is not achieved by having periodic elections of leaders. In the Marxist viewpoint, it is inevitable that ultimately, power will lie with the producers of wealth: with the workers.