The IETF is currently considering whether Singapore's legal climate for same-sex marriages makes it an unacceptable choice for holding meetings there. They're in a bit of a bind because they've already made non-refundable bookings there.
Meanwhile a leading US presidential candidate has made, as a centrepiece of his campaign, a promise to "temporarily" block all Muslim non-citizens from entering the USA. Should this come into effect, it would be unconscionable to block Muslims from attending international conferences and other events by holding them in the USA. Because larger conferences have to be booked far in advance, it would seem prudent to avoid booking US locations for 2017 and beyond until this issue is resolved.
FWIW just the thought of having to tick an "I am not a Muslim" box when entering the USA fills me with horror.
(I guess there's an economic hack available where you buy Muslim-ban-insurance to cover the cost of relocating and add that to the cost of a booking in the USA.)