Brian Williams speaks onstage at the New York Comedy Festival in November of 2014. Monica Schipper/Getty Images for New York Comedy Festival hide caption

itoggle caption Monica Schipper/Getty Images for New York Comedy Festival

During the 2012 campaign cycle, CNN was among several news networks that hosted Republican debates. Now, the GOP says it doesn't want to be on either that network or NBC. Joe Raedle/Getty Images hide caption

itoggle caption Joe Raedle/Getty Images

Meet the Press host David Gregory holds what he described as a high-capacity ammunition magazine during the Dec. 23 program. Uncredited/AP hide caption

itoggle caption Uncredited/AP