I’m not sure what you mean by “corrupt.” Both Lenin and Stalin were more than happy to murder civilians by the thousands (Lenin) or millions (Stalin) to attain political goals, and Stalin in particular murdered many who were closest to him, or in any sort of leadership positions (the purges) out of paranoia. Yes Obama cut his political teeth in uber politically corrupt Chicago, and surely that affected his Marxist ideals....but I don’t know that that makes him comparable to mass-murdering communists.
By corrupt I mean willing to compromise their principles for cash. Stalin got his gold by murdering perhaps millions in the frozen gold fields of Kolyma. Perhaps the remnant of America's fine political structure (the Constitution) is preventing Obama from killing 75 million Americans as his mentor, former Weatherman terrorist, Bill Ayers, laid down in his "Prairie Fire" book (dedicated RFK's murderer, Sirhan Sirhan).