Immigration or Invasion?

Screenshot_102915_113754_AMMayor Slay and citizens lobbying to bring Syrians to St. Louis; a Senate hearing that exposes there is no way to know who these people are; a Presidential Memorandum and resulting task force; and the president telling immigrants they do not have to assimilate. How are these connected, and is there more to the story than what meets the eye? Should we Americans be concerned?