Personally, I don't blame anyone other than the segment producer in this case. They were clearly so hard up to find someone to support their narrative that they didn't even bother vetting this d-bag. I'll also give some credit to Gretchen Carlson here for not losing her composure or getting totally trolled.
In case you're wondering how this guy managed to slip past the people who are supposed to vet on air guests, read this. It explains a lot about how Fox finds their anti-Obama guests, and is fairly frightening/disgusting when you really think about it.
Question: Should someone get fired over this, assuming they haven't already been?!?