[12423gsd]

While he was not a communist, his plans for social justice were very threatening to the establishment

If you read "Where Do We Go from Here: Chaos or Community?" (which he wrote towards the end of his life), he basically says that the Civil Rights movement needs to shift from racial agenda to an agenda of helping the poor. However he never presents an actual plan other than some vague idea of a massive transfer of wealth from the rich to the poor.

http://en.wikipedia.org/wiki/Poor_People%27s_Campaign

I'd go farther to argue that he's not a communist b/c he wasn't really thinking in those terms and he actively tried to avoid the label (that's why he took for ever to stand up against the war in Vietnam)