In his blog,
What Does the Prayer Really Say?, Father Zuhlsdorf recently published the following:
http://wdtprs.com/blog/2009/08/the-1964-hyannisport-conclave-catholic-leaders-teaching-catholic-pols-how-to-ignore-evil/
It appears that, even as early as 1964, the dissent in the Church took the form of an alternative magisterium, to which certain politicians appealed as though it exercised a higher authority than the Pope.