Indeed, the arguments supporting racism and white supremacy are NOT rational or moral arguments...they are, IMO, emotional arguments based on irrational biases which exist.  If your suppositions are true, then a rational/moral argument against racism would be wasted.  If that's the case, those persons susceptible to such racism would already hold that position when listening to individuals such as Spenser or Duke...."no harm, no foul".  I don't really believe they guys are "converting" many individuals....I think they're "preaching to the choir" of "already-racists" and feeding the feelings of being "white victims" by being censored and shouted down by these college audiences.  

I feel censoring these voices gives them far more power than allowing them to be heard and countering them.  They're not going to be gaining "converts' on the college campuses.  They WILL be gaining strength by becoming "victims of "liberal censorship"..Let's not play into their hands.  Gary Crum