Thanks for the gratuitous insult, but I think the world of my Irish ancestors.  I'm pleased you think they didn't kill any Americans, but I'm not certain that's true.  After the Know-Nothings started burning Catholic churches my ancestors built walls around their churches and posted armed sentries.  I hope they didn't pick off any Know-Nothings but I'm reasonably certain they were sorely tempted.

My point is that the fears that drive you were the same ones that drove the Know-Nothings back in the mid nineteenth century.  Substitute Muslim for Catholic, and six (used to be seven) Muslim ban countries for Ireland, and the rest is the same.