Ten Democratic presidential candidates debating tonight; Biden and Warren going head-to-head for the first time; Trump visiting city he called "rat and rodent infested mess"; Trump keeps defending John Bolton's ouster, says ex-National Security Adviser "was holding me back"; Trump says he won't make Pompeo serve as both Secretary of State and National Security Adviser; Former FBI official Andrew McCabe now at rise of indictment after Justice Department rejects his appeal to avoid prosecution; Trump answers questions from reporters; Trump: we had a "big meeting" today on guns; Wolf visits with Jimmy Carter as the former President warns against climate of hate in the U.S. via Knit