Yes, keep him out. He is a threat. He is a threat to your children who attend university. That is what he is good at... influencing the youth for evil. Good going, Canucks. eh.
Ayers and his ilk long ago figured out that to really bring down the US, free market capitalist System they needed to get to the youth through the educational systems. Their call for radical revolution/kill your parents style action was seen as never working.
Looks like they are well on their way to success. Canada sees him as the infiltrator he is.