The problem with Hassan was that he advocated extremist views,  which was a concern among many of his military peers, and he came from a Muslim background, which doubled the concern.  However, admin views toward not offending people of other religions led to an ignoring of these concerns, which ultimately led to the terrorist attack on U.S. soil.   That was the result of a "Good Samaritan" treatment of a clearly radicalized Muslim.

Muslim terrorism exists on a large scale throughout the world, including Europe.  It's a significant issue.

Concern about protecting Americans  from terrorism is characterized by the author as "a vitriolic campaign our immigrant roots, not to mention our Christian heritage and Pope Francis’ message of reaching out to those at the margins."

Actually, the concern about Muslim immigration from radicalized countries is based on concern for national security.  If it were merely based on ideas about race or religion, I'd be agin' it.