Although Steyn hits the nail on the head that you must have a base culture in order to assimilate newcomers into it, I do not feel at all optimistic that we are going to be able to put the "tolerance" genie back into her multi-cultural bottle.
The originators of the PC form of tolerance have been successful at putting it back in the bottle. Their solution?
Use two bottles. They put it back in their bottle, YOU must keep yours open.