Simply put, multiculturalism holds that the truth claims and morals from all cultures are equal, except judeo-Christian truth claims and morals - which are not to be tolerated. Multiculturalism is only a secondary problem. The number one problem is MORAL RELATIVISM. If there is no right and wrong, except what I feel is right or wrong, then I can do whatever I want. Of course, intolerance is the only thing that is wrong in moral relativism. All viewpoints are equally valid except the christian one.
When I hear this I just say, "Is that really true or is it just your opinion?"
That usually crashes their computer.