Forget immigration: The Islamic State may be the best reason yet to secure the U.S.-Mexico border.
But Taylor added that DHS has not seen any credible evidence of a threat from IS to targets on U.S. soil.
Does this sound familiar? It should: Texas Gov. Rick Perry warned the audience at a Heritage Foundation conference on border security and immigration in August that IS militants "may have already slipped across the Mexican border."
"I think there is the obvious, great concern that — because of the condition of the border from the standpoint of it not being secure and us not knowing who is penetrating across — that individuals from ISIS or other terrorist states could be," Perry said, although he conceded that there was currently "no clear evidence" that terrorists have entered the U.S. illegally across the southern border.