I remember reading that in Time magazine. It came to be known as the Altamont Rock and Roll murder. Mick Jagger in an interview said that they had no problems with the Hell's Angels in the UK, but it turned out that their US counterparts were psycopaths!
There is no political agenda. These blokes started out as a motorcycle group with a shared sense of freedom and wildness. Because of their strong "brotherhood" bonds, that no brother would have to fight alone, they became strong and more powerful as time passed and soon members in their organizations started to use this "power" for personal gains in criminal activity. There are many motorcycle gangs similar to the Hell's Angels and today there must be dozens of these "1%" gangs. Four of which have grown tremendously big and organized and are called The Big Four. They are the Hell's Angels, The Outlaws, Bandidos, and Mongols. In some ways they have given motorcycling a bad name, but despite this, many regular law-abiding citizens follow their trends and image (dressing style, patches, etc.) There is a group called the Harley Owners Group (HOG) who don the sleeveless jackets, patches, bandanas, bracelets, but are mostly white-collared weekend bikers who wish to look badass.
Cheers!
.......
I recall in a Rolling stones concert in the UK the band engaged the local Hell's angels chapter to be in charge of security and they had no problem. Then they tried to do the same in the US and a big fight broke out resulting in a spectator being shot and killed.