I (U.S. citizen) personally know highly-skilled software engineers who emigrated to the U.S. from Anglosphere countries to work at U.S. companies, who have since resigned and gone back to their home countries explicitly because of Trump's election. These aren't Middle-Easterners or illegal immigrants, these are white people for whom a $200k salary wasn't enough to convince them to endure a rising tide of nationalism. Skilled foreign workers are already selecting themselves out of our economy, regardless of country of origin. Not equivalent to the Nazi brain drain, though in an amusing twist I also know one American software engineer who has moved to Germany to ride out Trump.
Beyond the policies, there's also a signaling problem. I know several people who have taken a pass on U.S. jobs because of the uncertainty and growing anti-immigrant rhetoric. And they definitely don't trust the average American not to lump them in with targeted groups by virtue of being brown.
There are a lot of very smart people from Iran. Sure, the current travel ban is only a small portion, but Trumo has only been in power for just over month. There is no reason to think he and Bannon are satisfied.
