Given the evidence that crackdowns and reprisals generate further radicalism, why would you support further crackdowns and reprisals?
Emily - some long-overdue common sense, with regard the visitors visa program, for 90 days or less, enacted for business and tourism, is surfacing. This visa waiver program has been in effect for a long time and allows countries in the program (about 38) to come into the US without a visa. It has been the subject of criticism as a source of "visa overstays" has been a huge number of "visitors visa" people who have not applied for any upgrade in visa status to allow long-term residency or application for citizenship.
So, millions who come through the airports can disappear under-the-radar, and do who knows what. Looking at this is/or will be a crackdown of sorts. It is the most obvious place that we can fix quickly.
They are "guests who don't leave."