Why and when did "born again" Protestants become so annoying to many in American civil society?

"In pursuit of an answer Hart, a professor of church history at Westminster Theological Seminary in Escondido, Calif., ranges nimbly across American Protestant history in the 19th and, especially, 20th centuries. When he comes to the upheaval of the 1960s, he remarks that 'the United States entered a new phase of cultural history in which Protestantism no longer yielded a common sense of purpose and set of standards as it once had'...the change from 'a Protestant to a post-Protestant society...made evangelical politics appear to many as old-fashioned, if not a little obnoxious.'"