Kennedy stood on a ticket of racial and economic justice, non-aggression in foreign policy, decentralization of power and social improvement. A crucial element to his campaign was an engagement with the young, whom he identified as being the future of a reinvigorated American society based on partnership and equality.
Kennedy's policy objectives did not sit well with the business world, in which he was viewed as something of a fiscal liability, opposed to the tax increases necessary to fund such programs of social improvement. When verbally attacked at a speech he gave during his tour of the universities he was asked, "And who's going to pay for all this, senator?", to which Kennedy replied with typical candor, "You are." It was this intense and frank mode of dialogue with which Kennedy was to continue to engage those whom he viewed as not being traditional allies of Democratic ideals or initiatives.
It has been widely commented that Robert Kennedy's campaign for the American presidency far outstripped, in its vision of social improvement, that of President Kennedy; Robert Kennedy's bid for the presidency saw not only a continuation of the programs he and his brother had undertaken during the President's term in office, but also an extension of these programs through what Robert Kennedy viewed as an honest questioning of the progress that had been made in the 5 years since the President's death. Kennedy openly challenged young people who supported the war while benefiting from draft deferments, visited numerous small towns, and made himself available to the masses by participating in long motorcades and street-corner stump speeches (often in troubled inner-cities). Kennedy made urban poverty a chief concern of his campaign, which in part led to enormous crowds that would attend his events in poor urban areas or rural parts of Appalachia.
http://en.wikipedia.org/wiki/RFK#Presidential_candidacyMcGovern sought to pull that coalition back together in 1972.