King was more than just another Socialist. His famous march on Washington, succeeded in bringing together various Marxist leaders & groups, which had not previously worked together--they were rivals for the power they expected--i.e., as believers in the Marxist view of historic inevitability. But they came together, all seeing King as useful, for apparently having the American establishment on the run.
Beck chooses to quote King out of context, and to pretend--there is no better word for it--that he was a great libertarian. He was the absolute opposite.