Is The U.S. Government Apprehending 7 Suspected Terrorists A Day On Southern Border?

Vice President Mike Pence, speaking in Dallas, said that "along the southern border of the U.S.," the government apprehends "seven individuals a day who are either known or suspected terrorists." Is that true? We asked Gardner Selby of PolitiFact Texas. You can read the fact-check here: http://www.politifact.com/texas/statements/2018/feb/21/mike-pence/pants-fire-mike-pences-claim-about-nabbing-7-terro/