Hardball with Chris Matthews 09/18/15

Clinton fires warning shots at Sanders, Biden

Hillary Clinton is sending signals to rivals Bernie Sanders and Joe Biden by signing up endorsements from Vermont and New Hampshire and throwing an elbow at Vice President Biden over a credit card issue. Heidi Przybyla, Cornell Belcher and Sabrina Siddiqui make up the Hardball Roundtable. ... more Duration: {{video.duration.momentjs}}