Well, as an Australian I'd hope they'd not come here either, happy to have refugees and help then out as much as possible but not Americans.
As to brain drain, you come from a country that's destroying the planet, acts like a spoiled child when it doesn't get it's way, (look at the reaction to the ICC arrest warrants for Israel) you've created a monster that has little to admire, the "brains" that created all that will hopefully stay there.
This is a country that has threatened to invade the Hague if any US person or allly is indicted by the ICC for example. Churlish doesn't even begin to describe it, stay there.