Some information from the Bishop's Task Force that looked at this issue:
On the question of calls for denying Communion or public calls for refraining from Communion, our conference is not united, with several bishops sincerely convinced this is necessary and many others who do not support such actions.
Our consultations with moral theologians and canonists warned us that such steps could raise serious questions about Catholic teaching and the application of Canon Law. State Catholic conference directors warned about a negative impact on faithful legislators, the Catholic community, and the role of the Church in public life.
In our ad limina visits, many of us raised these questions. As many of you know, Vatican officials offered both principles and advised caution and pastoral prudence in the use of sanctions. In recent days, I have once again been in contact with Cardinal Ratzinger both by letter and telephone calls. He has offered some observations for our work which he specifically asked not be published, but which I wish to share with you. The first is a recognition that it is up to us as bishops in the United States to discern and act on our responsibilities as teachers, pastors and leaders in our nation. He expresses his respect for the role of our conference and the bishops in the United States in carrying out these responsibilities.
Having said this, Cardinal Ratzinger speaks about
WHAT constitutes manifest grave sin and obstinate persistence in public life,
stating that consistently campaigning for and voting for permissive laws on abortion and euthanasia could meet these criteria.
Cardinal Ratzinger outlines
HOW a bishop might deal with these matters, including a series of precautionary measures involving a process of meeting, instruction and warning. This process involves meeting with the person and providing instruction on Catholic moral teaching. Cardinal Ratzinger suggests informing such persons that if they reject Catholic moral teaching in their public actions, they should not present themselves for Holy Communion until their situation has ended. Using the precedent of our teaching and practice in the case of a person in an invalid marriage, the Cardinal recognizes that there are circumstances in which Holy Communion may be denied.
He also indicates that in these cases a warning must be provided before the Eucharist can be denied.
I would emphasize that Cardinal Ratzinger clearly leaves to us as teachers, pastors and leaders
WHETHER to pursue this path. The Holy See has repeatedly expressed its confidence in our roles as bishops and pastors.
The question for us is not simply whether denial of Communion is possible, but whether it is pastorally wise and prudent. It is not surprising that difficult and differing circumstances on these matters can lead to different practices. Every bishop is acting in accord with his own understanding of his duties and the law.
It is important to note that Cardinal Ratzinger makes a clear distinction between public officials and voters, explaining that a Catholic would be guilty of formal cooperation in evil only if he were to deliberately vote for a candidate precisely because of the candidates permissive stand on abortion. However, when a Catholic does not share a candidates stand in favor of abortion and/or euthanasia, but votes for that candidate for other reasons, it is considered remote material cooperation, which can be permitted if there are proportionate reasons.
Therefore, based on the traditional practice of the Church and our consultation with members of our conference, other episcopal conferences, distinguished canonists and theologians,
our Task Force does not advocate the denial of Communion for Catholic politicians or Catholic voters in these circumstances.
No one should mistake our task forces reservations about refusing Communion or public calls to refrain from Communion as ignoring or excusing those who clearly contradict Catholic teaching in their public roles. Those who take positions or act in ways that are contrary to fundamental moral principles should not underestimate the seriousness of this situation. We insist that they must study Catholic teaching, recognize their grave responsibility to protect human life from conception to natural death, and adopt positions consistent with these principles.
However, in our view the battles for human life and dignity and for the weak and vulnerable should be fought not at the Communion rail, but in the public square, in hearts and minds, in our pulpits and public advocacy, in our consciences and communities.
Based on our consultation process, there is significant concern about the perception that the sacred nature of the Eucharist could be trivialized and might be turned into a partisan political battleground. Expecting a minister of Holy Communion to make these judgments would create great pastoral difficulties. We do not want to encourage confrontations at the altar rail with the Sacred Body of the Lord Jesus in our hands. This could create unmanageable burdens for our priests and those who assist them and could turn the Eucharist into a perceived source of political combat.
Other questions were raised about where the process might lead--who would be impacted and what other issues might lead to denial of Holy Communion. We fear that it could further divide our Church and that it could have serious unintended consequences.
For example, it could be more difficult for faithful Catholics to serve in public life because they might be seen not as standing up for principle, but as under pressure from the hierarchy. We could turn weak leaders who bend to the political winds into people who are perceived as courageous resistors of episcopal authority. In the past such actions have often been counter-productive. We also fear it could push many people farther away from the Church and its teaching, rather than bringing them closer.
In light of these and other concerns, the task force urges for the most part renewed efforts and persuasion, not penalties. We urge new efforts to teach clearly, advocate effectively, organize and mobilize Catholic laity and to engage, persuade, and challenge Catholic politicians to act on the moral teaching of our Church.
Disciplinary actions are permitted. Indeed, in the guidance I just shared with you, they are discussed.
But they should be applied when efforts at dialogue, persuasion and conversion have been fully exhausted. There is a wide range of affirmative approaches used by members of our conference. These need to be practiced more widely, more strategically and more effectively.
http://www.usccb.org/bishops/intreflections.shtml
