Why do some Catholics oppose the bishops teaching on "political" issues?

My former law professor Fr. Robert John Araujo, SJ answers that question in this blog post over at The Mirror of Justice:  Enemies Within. As Fr. Aruajo notes, the push by many Catholics on the Left to silence the bishops from speaking out on issues related to marriage, abortion and activist government comes from a failure to properly stand up to the forces within out society that are opposed to the Gospel and to the basic principle of the sanctity of human life.  This leads, of course, to retaliation against the Church from the secular powers that have become captive to an ideology that disparages faith and family.  But such retaliation, as Fr. Araujo explains, should not intimidate the Church into silence over its core teachings involving family life, the dignity of human life, and the proper sphere of government action:

This is how tyrants operate; but tyranny should not stop any of the faithful from the call to and the responsibilities of discipleship. There fact that there are divisions within society should not preclude the truth about important matters from being spoken. The argument that there is no truth or different kinds of truth about the same issue is no argument at all; rather it is an exercise of a will unhitched from objective reason that wants to avoid truth and its objectivity and its beneficial meaning for the common good.

Give all of Fr. Aruajo's post a read.