I expect most DEFCON people would gladly accept the inconvenience of a smaller choice of flights, if it removed the possibility of being detained while ensuring the conference is still well-attended. You can't realistically move DEFCON too far, and the other options (Mexico, Caribbeans...) are not exactly a step forward in terms of liberal rule of law.
I think the main problem will always be people who can't (or won't) cross the US border at all, no matter how easy it is. I expect this number is significant among the DEFCON crowd. Still, at some point, the organisers will have to consider whether keeping those types around is worth putting all their non-US guests at risk of draconian imprisonment.
I think the main problem will always be people who can't (or won't) cross the US border at all, no matter how easy it is. I expect this number is significant among the DEFCON crowd. Still, at some point, the organisers will have to consider whether keeping those types around is worth putting all their non-US guests at risk of draconian imprisonment.