In 1968, the assassination of black civil rights activist Martin Luthor King and then of Robert (Bobby) Kennedy, who was running for the presidency and was also a peace candidate, had a major effect on the hippy movement. After the assassinations, many hippies doubted that change could ever come through the existing institutions.
A group called the Yippies (Youth International Party) were the most politically active hippies. Led by Abbie Hoffman (who was arrested 52 times) and Jerry Rubin, they tried to change the existing politic system. In 1968 they tried to disrupt the Democratic Party Convention, which became a battle between the Chicago police and the anti-Vietnam demonstrators in which a number of demonstrators were killed and hundreds arrested.
However, not all Hippies got directly involved in politics. Many just lived alternative lifestyles within society. They are often seen as the people who popularised the use of marijuana and hallucinogenic drugs, enjoyed psychedelic music, and practiced free love.
Many other hippies, however, preferred to break from society altogether and created their own mini-societies - or communes - based on their alternative values. They believed the communes would be better than the society they left, but most of the communes failed to live up to their hopes and fell apart, though some, like Nimbin in Australia, are still around today.