Covering JFK: How presidential security has changed

President Barack Obama travels in a heavily armored Chevrolet Cadillac, dubbed the Beast, specially designed to protect the head of state and has a Secret Service made up of 3,200 special agents and 1,300 uniformed officers. But PBS NewsHour co-founder Robert MacNeil remembers the 1960s when it was not nearly as difficult to get close to the commander-in-chief.