Most everyone agrees with some amount of social policy to help those in need in some ways. West's question gave Biden the easy opportunity to laugh at the Marxist question immediately, then respond and clarify how he does not hold Marxist views, despite certain obvious points of agreement with Marx's observations and thoughts. This would have shown how ridiculous he thought the question was and correted the misconception that ever led an idiot to ask it in the first place.
But Biden didn't do anything of the sort. He didn't 'laugh' and totally clam up because the question was ridiculous. He didn't give NO explanation, even an explanation of why the question was baseless and out of line, because the question was ridiculous. He realized the interview was asking for an amount of openness that he and Obama are very open about NOT being willing to give. After Biden's comments about it being patriotic to have your taxes increased and Obama's huge error with "Joe the Plumber" (his error being that he was too open, too honest), you can be sure Obama's campaign is advising them both to step even more lightly around this issue than before, so close to the election.