The following article is interesting mainly for the comments found below it.
Catholic bishops share in the charism of infallibility when they speak on faith
and morals, in conjunction with the Holy Father. That is part of the magisterium,
the teaching authority by which we know the pure truth of the Gospel. That magisterium
cannot be broken because it comes from God himself (Mt 16:18).
When they stray from faith and morals, bishops are no more likely to be free from error than any other well-informed people. On many important subjects in the 1970s and ’80s, American bishops brought their prestige to bear against many policies Ronald Reagan favored.