Ben Carson was put on the defensive on Thursday, with reporters pressing him about a series of reports that have sprung up questioning the factual accuracy of his past statements. As Carson has gained in the polls, so has media scrutiny of the 64-year-old retired pediatric neurosurgeon and Republican presidential candidate, whose past and present statements have drawn no shortage of curiosity and interest. On Thursday, during a stop on his book tour, Carson was pressed on everything from a report that questioned past claims of his physical violence toward others, an interview in which he appeared to struggle with...