Not all moral issues have the same moral weight as abortion and euthanasia. For example, if a Catholic were to be at odds with the Holy Father on the application of capital punishment or on the decision to wage war, he would not for that reason be considered unworthy to present himself to receive Holy Communion. While the Church exhorts civil authorities to seek peace, not war, and to exercise discretion and mercy in imposing punishment on criminals, it may still be permissible to take up arms to repel an aggressor or to have recourse to capital punishment. There may be a legitimate diversity of opinion even among Catholics about waging war and applying the death penalty, but not however with regard to abortion and euthanasia.

For the Church to start picking political candidates would be a death-knell to its ability to be a trans-political religious organization. Separating the Church from electoral politics is in fact a defense of Catholicism from the depredations of politicized religion that has so infected the Protestant right, which is now a de facto branch of one political party.

But is abortion different? Is the contempt for human life that any abortion inherently embodies such a social evil that no politician can be permitted to call himself a Catholic and support the right to choose it? That is indeed a critical question, and conservative Catholics are not wrong to raise it. But there is a distinction between support for the morality of abortion and reluctant support for a woman's right to choose such a moral wrong. It should be possible, if difficult, for a Catholic politician to affirm the evil of abortion but to defer to the political freedoms inherent in a liberal polity--specifically control over one's own body--in most cases. Mario Cuomo tried to define such a position, with mixed success. You can differ with him (as I once did). But it seems an extreme measure to punish such a thoughtful statement with effective ex-communication.

In my view, Kerry's support for partial birth abortion and the absence of any statement I know of in which he speaks of the profound moral cost of abortion certainly puts him on the fringe of legitimate Catholic doctrine. Bill Clinton's belief that abortion should be "safe, legal, and rare" is far more defensible, because it at least concedes the principle that just because something is and should be legal doesn't make it right. But even then, the hierarchy's criticism of such a stance need not degenerate into a policy of purging Catholic politicians from their own church. It should be possible--in fact, there is no long-term alternative to reducing abortion--to make the important public case in defense of unborn human life, while avoiding the painful and dangerous business of denying sacraments and getting embroiled in presidential politics.