He's also dangerous because of his age. It's hard to paint somebody who's only 37 as being "yesterday" in terms of foreign policy. Plus you can't dismiss him as senile and young voters may identify with him.
The fact that there are virtually no other senators in that age bracket is problematic.
Cotton fought in foreign lands to enslave Americans with the Patriot Act extension? What's the point? Why fight in Iraq if you're simply going to discard the constitution?