The issue isn't whether immigrants are good for the US. Or course they are. The issue is whether Democrats will use all appropriate indices of violence as valid screening criteria, and whether Republicans will tighten gun background checks.
Should the US admit 10,000 Syrian refugees? All other things being equal, the answer is obvious: of course. This country is built on immigrants — people who look different but turn out not only to fit in but to make dramatic contributions to our country. Think Edward Teller. Think Albert Einstein. Think Elie Wiesel. If anything, in a world flooded with millions of Syrian refugees, the US should be embarrassed to be debating the admission of such a small number of potential Syrian refugees.
Unfortunately, all other things are not equal. Following the Paris terrorist attacks, people justifiably question the degree of security in free societies.