I will re-suggest this PDF file that was passed out to us last Sunday in church. On page 2, you will find 10 questions that the United States Conference of Catholic Bishops formulated to question/test each candidate’s approach on each issue. For a minute, focus on what this consensus poses, rather than focusing on what the individual left and right leaning bishops positions are. There really is no clear cut decision between the major candidates.
Except that separation of church and state applies only to the state, not to the church.
a devout roman catholic hear, i attend church every sunday. our priest makes a specific point that this is not his church, it is God’s church. and that he has no right to deny anyone access to the house of God. the church is open to the rich, the poor, the catholic, the not so catholic, straights, or gays, whomever wishes to come is welcome. while i am firmly opposed to abortion, i am voting for Kerry.
i hasten to point out that the pope expressed his opposition to the iraq war some time ago.
And that’s just a summary. A more detailed look at the issues from a RC point of view is found here: http://www.usccb.org/faithfulcitizenship/bishopStatement.html
Peace.
IANAC, but I can clarify this a little. To take the example of unjust wars, no one ever goes around proclaiming his support of unjust war. Anyone who did so would certainly be beyond the pale from a Catholic perspective and universally recognized as deranged. On the other hand, people often disagree on whether a specific war meets the critera for justice or not. This may be a matter of disagreeing over facts, or differing on calculations of necessity and risk, rather than disagreeing on fundamental moral convictions. It is at least concievable (even plausible, I think) that Bush agrees with the RCC’s just war criteria (at least in broad outline), while disagreeing with the Pope on whether the invasion of Iraq was justified (based, for example, on differing estimates of the immediate threat Iraq posed to the US). If so, his error is practical, not moral.
(Likewise, surely no one advocates the death penalty except in cases of extraordinary necessity; they just dissagree with the Vatican on which cases those are.)
No such justification is possible for a truly pro-choice position. Like unjust war, murder (the deliberate taking of innocent human life) is tautologically immoral: to advocate murder is to be morally deranged. Since unborn persons are necessarily innocent (in the relevant sense) and abortion, by definition, is the deliberate act of terminating the fetus’s life, abortion is a necessarily immoral act. Opponants will argue, of course, that a fetus is not a human life in the relevant sense. If they are wrong, however, they are without excuse, for the same reason that one’s honest belief in the sub-human status of a racial group compounds, rather than extenuates, guilt: failure to recognize humanity (or personhood) where it is present is itself a moral failure. (I personally am not convinced that advocates of abortion are wrong about the status of fetuses, but I recognize the formal validity of the Catholic argument.)
FTR, it should be obvious (if not compelling) how oposition to stem cell research follows directly from Catholic reasoning on abortion.
The same-sex marriage thing, though, has me baffled! 
(I understand [and disagree with] Catholic oposition to same-sex sacramental marriage, but I fail to understand the Catholic position on civil marriages, or how the civil recognition of same-sex unions could be morally wrong in the same fundamental way that muder is.)
Does anyone have poll numbers showing what percent of US Catholics support either candidate? Another relevant issue here to who the Roman Catholic heirarchy tends to support is that Bush is in the pocket of the right wing Protestants. Much of their agenda isn’t what Catholics want. Catholics don’t support school prayer. The don’t want the Protestant majority leading their kids in prayer. They think the priests can handle religious stuff just fine.
Actually (and regrettably, in my opinion as an otherwise pro-life Catholic), the Catholic Church explicitly forbids abortion for any reason, including the life of the mother. In his encyclical Humanae Vitae (1968), Pope Paul VI wrote,
It’s a little more complicated than that. Evil acts are not permissible even if they have good effects, but good acts are permissible even if they have evil effects. If, for instance, a pregnant woman is discovered to have a serious cancer, and chemotherapy is necessary to save the woman’s life, it’s allowed, even though the death of the fetus will be an almost certain consequence of the chemotherapy. Of course, alternatives should be sought (perhaps delaying the chemo until after birth, or using some more targetted treatment) and every effort should be made, consistent with saving the mother, to also protect the fetus. It would also be allowable for the mother to decline the chemo in the hopes of saving the child, even if this is likely to result in the death of the mother.