"The key, it seems, is that Americans are particularly concerned about immigrants being criminals or refusing to assimilate."

From this article - https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2889665

"many Americans will change their positions on immigration policy if you give them a reality check on some of these other anxieties."

"After being exposed to the information, Republicans in particular became likely to favor increased legal immigration, as well as to sign a White House petition to increase the number of green cards, which would allow more foreigners to live in the United States permanently."

"Many political scientists tend to think that our beliefs are deep-seated and difficult to change. That’s why the results of an experiment last year, which showed that door-to-door canvassers can reduce prejudice against transgender people, were so stunning."

Study where canvassers reduced prejudice: http://science.sciencemag.org/content/352/6282/220