Frank named the date by which he believes that candidate should give up the fight: June 3rd, the day of the South Dakota and Montana primaries. He added that the trailing candidate should drop out "probably sooner" than that.
Clinton trails Barack Obama 1634 to 1495 in the most recent CBS News delegate count, and it is virtually impossible for her to close the gap in pledged delegates before the Democratic National Convention in late August. Barring a major surprise, Clinton's hopes rest largely on convincing the superdelegates – the party insiders who hold nearly 800 delegate votes – to swing significantly in her favor. About 300 such delegates have yet to announce who they support.