Democratic presidential candidate Bernie Sanders on Thursday responded to criticism from his Senate colleague, Claire McCaskill of Missouri, that he is too liberal to credibly challenge Hillary Clinton.
“To the best of my knowledge, this is the first time that a colleague has attacked me,” said Sanders, a Vermont socialist who joined the presidential race about two months ago, in an interview with Bloomberg Politics' Mark Halperin and John Heilemann. “You'll have to ask Senator McCaskill why.”