Today, at the grocery store, the bagger of my goods was a man of Mexican heritage with a Mexican accent. He was in his fifties, about five-five, brown-skinned, graying temples. He wore glasses, had a pleasant smile and a pleasant demeanor. When I first saw him, I did a double take, however. He was a dead ringer for a physician of my aquaintance, Dr. H.
Dr. H is originally from Syria.
What's to stop a Mexican-appearing wannabe-jihadi from sneaking in over the southern border among those yearning to be free? Answer me that, Gray Davis.

