GREENVILLE, South Carolina--Outside Tommy's Ham House here this morning--where Mitt Romney and Newt Gingrich scheduled back-to-back visits--a boisterous crowd of young, fresh-faced supporters was waving Romney signs and chanting, "MITT! MITT! MITT!"But this wasn't a grassroots youth movement rooted at the University of South Carolina. No, many of the students cheering on the candidate told BuzzFeed they were actually BYU students and young Mormons from D.C. and Virginia who traveled to the Palmetto State to give their coreligionist's presidential effort a much-needed jolt of energy.Kat Wardle, a 23-year-old BYU student who is spending the semester in Washington, D.C., said she...