Because of what he did, Lenin is vilified by the capitalist class, probably more vilified than any other Marxist figure in history including Karl Marx himself. To reduce Lenin's contributions to the worldwide class struggle to a brief blog entry is beyond ludicrous, but let's just note four:
- He defined and explained imperialism, the highest stage of capitalism which had not yet hit its full flowering during Marx's lifetime, and thus drew workers and peasants from every country on the globe into the embrace of revolutionary socialism.
- He expanded on Marx's theory by defining and explaining the national question--the special oppression of national minorities in every class society--and made the struggle against racism and for the right to the self-determination of oppressed nations a central feature of revolutionary socialism. Ever after, Marx and Engels' slogan "Workers of All Countries Unite!" would be transformed to "Workers and Oppressed of All Countries Unite!"
- He was not only a theoretician and writer but an organizer, orator and practical revolutionary, under whose leadership the Bolshevik Party became the vehicle for the liberation of the Russian (and Georgian, and Chechen, and Jewish, and all the many other minority nationality) masses. I'm generally pretty leery of Wikipedia when it comes to matters of the class struggle, but its definition of Bolshevism isn't half bad: "an organization of professional revolutionaries under a strict internal hierarchy governed by the principle of democratic centralism and quasi-military discipline, who considered themselves as a vanguard of the revolutionary proletariat."
- He built on Marx and Engels' study of the state, its historic role in class society, its tasks in the period of building socialism, and its future withering away, and led the opening efforts to create the world's first revolutionary socialist state in the USSR.
Which brings us back to Lenin. As has been hilariously noted elsewhere, the coincidence of the first Earth Day falling on his 100th birthday deeply disturbed some in 1970. From Wikipedia: "Time reported that some suspected the date was not a coincidence, but a clue that the event was a 'Communist trick,' and quoted a member of the Daughters of the American Revolution saying, 'Subversive elements plan to make American children live in an environment that is good for them.'"