What is This GOP Race About? S.C. Debate Shows Trump’s Outsize Role Weeks Before Opening Contest; Donald Trump, the New George Wallace? Head of Segregationist’s 1968 Bid on GOP Front-Runner’s Racism; “He Has Summoned a Political Revolution”: The Nation Magazine Endorses Bernie Sanders for President; Flint Doctor Mona Hanna-Attisha on How She Fought Gov’t Denials to Expose Poisoning of City’s Kids; Emergency for Democracy: Unelected Manager Who Caused Flint Water Crisis Now Runs Detroit Schools.