Terry:
But Erin Hills will get the first real close-up evaluation by the USGA over Cog Hill when it hosts the US Amateur coming up. If EHills "passes" that test (similar perhaps to how Merion got back into the mix by hosting the US AM), I think they'll get the US Open before Cog Hill. Comments about a course's worthiness from strictly an architectural standpoint are a lesser concern these days, it seems, than in the past. Essentially the USGA seems to doing an "over-the-bar" evaluation of Open courses, and if they can pass that test (is it stern enough? can it test the best players without being ridiculously hard?), other considerations take over (logistics, regional distribution, willingness to host).
Jay:
WStraits is hosting two PGAs, one Ryder Cup, with the US Women's Open just down the road at Blackwolf Run, all within the next several years. I'm sure Herb Kohler would love a US Open, but the Wisconsin golfing well isn't that deep.