I can only speak anecdotally but I know of a number of entrepreneurs/founders who have decided to set up shop elsewhere, in Canada for example, because of concern about the perceived restrictive and hostile immigration environment in the U.S.
Personally I've travelled to the US many times over the last 9 years from the UK (I don't want to move there, but have been happy to travel), but have done so less frequently since Trump was elected. No particular reason, it just feels a bit "dirty".
Are there any other factors that affect the rate?