Some of you have told Senator John Kerry and other prochoice Catholic politicians not to receive Communion in your dioceses. Others have gone so far as to say that Catholics who vote for a prochoice politician should not consider themselves in full communion with the church and are therefore unworthy of receiving the Eucharist. Most of you, however, have abjured these tactics, saying you do not want the Eucharist to be used as a weapon. Still, you have defended the right of any bishop to exclude prochoice politicians from Communion.

This is confusing. As John F. Kavanaugh, SJ, wrote in America (July 19-26), “Some Catholics have wondered whether mortal sins vary according to states and dioceses.” Nor is it clear what you realistically hope to accomplish, or are willing to tolerate, when it comes to changing abortion law in the United States. What sort of political compromise, if any, are you willing to work for and live with?

The church’s position on abortion seems straightforward enough: Innocent life is to be protected from the moment of conception. Complications soon arise, however. In Catholic teaching, exceptions are not allowed even for abortions following rape or incest. Is it your position that this teaching should be enacted into civil law, and that Catholic politicians who do not work vigorously toward this end are not in full communion with the church? Presumably, most of you would answer no, agreeing with St. Thomas that an unenforceable law, or a law that is perceived to be unjust, undermines the very idea of law itself. If morality and law cannot be separated, they are nonetheless distinguishable. Not everything sinful need be illegal. In a democracy, law must rest on the consent of the governed. That means living with some evils to avoid greater ones.

One thing is clear about the abortion debate in the United States: There is no consensus for making all abortions illegal. Nor is there a consensus for subjecting women or doctors involved in abortions to criminal penalties. Are the bishops advocating the recriminalization of all abortions-or something short of that? If criminalization is the goal, what penalties would you think just for the guilty? Would the father be subject to criminal penalties as well as the mother and doctor? You have a responsibility to grapple with the practical as well as the moral dimensions of public-policy issues you seek to influence.

The Catholic Church has waged a courageous, often thankless fight against abortion. It has been right to do so, and it has provided an invaluable witness to the intrinsic value of life in the womb. But let’s be frank. In the aftermath of the sexual-abuse crisis, the credibility of Catholic bishops on issues related to sexual morality is greatly diminished. Trust will not be restored soon or easily. The church’s prohibition against contraception, which is inscrutable to most Americans and unconvincing to most Catholics, also weakens its case against abortion. Worse, the church’s refusal to condone the use of condoms for married couples, even when one partner is HIV-positive, is morally obtuse at best.

Simply put, the church’s absolutist rhetoric often undermines your case against abortion, alienating potential allies and placing impossible demands on Catholic politicians. Thirty million American women have had abortions. A way must be found to enlist the good will and eventually the consent of these women if abortion law and practice are to change. The church hasn’t figured out how to do that. As Archbishop William J. Levada recently wrote, “while bishops have long been engaged in teaching and internal church ‘dialogue,’ that dialogue has not been effectively engaged for many Catholics in political life and in American culture at large.” You need to redouble your efforts at dialogue, not because you are wrong, but because you are right. As such, it is imperative that you find a better way to make your case.

The give and take of democracy is based on the implicit willingness of adversaries to compromise, even on questions of how best to uphold fundamental morality. Slavery was a great evil, yet not even Abraham Lincoln sought to forcibly abolish it where it was deeply rooted. Instead, he embraced an incremental approach, insisting that it not be extended to new territories or states. He thought that once slavery was contained it would collapse of its own inherent contradictions. Catholicism possesses the intellectual and moral resources to help craft such a compromise on abortion. Yet too many Americans, including Catholic Americans, think the church will tolerate only one solution to this dilemma. To be persuasive in the long run, you must show that more than one path is possible.