Sen. Ted Cruz attends campaign event in Boone, Iowa

Sen. Ted Cruz (R-TX), (C), 2016 Republican presidential candidate, makes remarks to supporters, surrounded by media, as he campaigns at the King's Christian Bookshop, January 4, 2016, in Boone, Iowa. Cruz is running against a large field of GOP candidates, including real estate mogul Donald Trump, former Sen. Marco Rubio and retired neurosurgeon Ben Carson, Iowa's first-in-the-nation caucuses are February 1. Photo by Mike Theiler/UPI