One of the most valuable aspects of our time is the ease with which ordinary people can live for a decade or more in a country not of their birth, their extended family, or even because of a particular job or education. You can go live somewhere else, without having to irrevocably give up your place of origin, and all that went with it.
Trump is attacking refugees, with an order issued at a time of remembrance for refugees we failed in their time of need.
Trump is attacking people who played by the rules, who navigated a difficult bureaucracy, who are hoping to find a life that is safe for them, better for them.
Trump is attacking the fragile fabric that ties open minded nations together, by attacking the ability of our individual citizens to live in other nations for a time, and to build connections across borders.
Hopefully, the incompetence of the attack, coupled with the vigorous response of people who understand the seriousness of this, will mitigate the harm.