Over a long career, as Democratic Congressman, Chicago mayor, ambassador, and chief of staff in the Obama White House, Rahm Emanuel has been a key and combative moderate in showdowns over health care and the economy. He tells "Sunday Morning" national correspondent Robert Costa that his fight, now and in the future, is bigger than him and his party. He talks about addressing the Democratic Party's progressive wing leading up to the midterms, and fighting the Trump administration.