U.N. Ambassador Susan Rice, touted as a possible successor to Secretary of State Hillary Clinton, went to Capitol Hill on Tuesday to meet with a small group of Republican Senate critics. They are unhappy with comments Rice made on TV shortly after the Sept. 11 attack on the U.S. consulate in Benghazi, Libya, where the ambassador and three others died. They say she incorrectly characterized the violence as a response to an anti-Islam video. After the closed-door meeting, the senators said they were more troubled than ever, and one promised to block her potential nomination. But it's unclear whether their views are gaining momentum.