To everyone picking apart what I said, I should really clarify. I wasn't saying that we shouldn't ever judge anyone because morality is relative, I was saying that basing an entire argument upon your own personal morals (free speech is good so if you punch white supremacists then you're bad) shouldn't be done because morality is relative. It's not an effective argument, since it's similar to arguing as a Christian to an Athiest that they should sell all their possessions and give the money to the poor because that's what Jesus told the rich man to do. That might be a good thing for them to do, but that doesn't mean the other person will agree to do so because the son of a God they don't believe in said so. 

If you absolutely have to use morality in an argument, common ground should be established first. Saying "Well, the second amendment says..." won't work unless both of you personally agree with the second amendment and what it states. If both of you agree that free speech is inherently a good thing, using it as a point of argument is useless. If you don't, then you should argue using different appeals rather than continuing to just say that your morals say you're right. If you can't manage to get anywhere with different appeals, then maybe your opinion isn't as strong as you thought. 

Of course, there's nothing wrong with trying to change someone's mind on the moral issue in the first place. I'm making an argument that morality is relative and has no inherent basis beyond common human instincts. Laws against, say, murder make sense because humanity as a whole can agree that just flat out killing someone is bad. I don't think that every aspect of action pertaining to what you could consider morality is relative, because as a species we do share some inherent instincts that we consider morality. We aren't hunter gatherers anymore, though, and in our complex societies and cultures morals can be heavily divergent. Attempting to change someone else's morals, either through a one-on-one conversation or massive cultural movement that could end with the spilling of blood, is a natural thing and I'm not saying it should never be done. On the contrary, I think it should be done more often.