Rob, There is one part of your article I must take issue with.
"One prominent bishop, Raymond Burke of St. Louis (one who said he would deny communion to Kerry), even later clarified that it would not be sinful to vote for Kerry, if an individual had reasons to vote for him that overarched the issue of abortion. Essentially, the Church has said that, while it clearly does not support abortion, it is not sinful to support the right to choose."
Archbishop Burke in his letter clearly states that there is no issue that overarches abortion or safeguarding the right to life. The Archbishop states, "But there is no element of the common good, no morally good practice, that a candidate may promote and to which a voter may be dedicated, which could justify voting for a candidate who also endorses and supports the deliberate killing of the innocent, abortion, embryonic stem-cell research, euthanasia, human cloning or the recognition of a same-sex relationship as legal marriage. These elements are so fundamental to the common good that they cannot be subordinated to any other cause, no matter how good," ("On Our Civic Responsibility for the Common Good," section 39).
And actually the Church does state that it is sinful to support the right to choose, because that implies that a person is not morally opposed to the occurence of abortions in a country. In Cardinal Ratzinger's letter on "Worthiness to receive Holy Communion. General Principles," he states that,
"A Catholic would be guilty of formal cooperation in evil, and so unworthy to present himself for Holy Communion, if he were to deliberately vote for a candidate precisely because of the candidate’s permissive stand on abortion and/or euthanasia. When a Catholic does not share a candidate’s stand in favour of abortion and/or euthanasia, but votes for that candidate for other reasons, it is considered remote material cooperation, which can be permitted in the presence of proportionate reasons."
So the question then becomes what is proportionate reasoning. I do not wish to propose an answer to that question here, but I do wish to point out two notes of clarity on that statement, both of which are implied earlier in the document. First, Ratzinger states,
"This cooperation can never be justified either by invoking respect for the freedom of others or by appealing to the fact that civil law permits it or requires it." Which means voting for a candidate BECAUSE they support the right to choose is cooperating in moral evil. Now voting for a candidate, as Ratzinger states, who is pro-choice because of other moral goods that candidate promises and not because of him/her being pro-choice is not cooperating in moral evil.
Secondly, Ratzinger states, "Not all moral issues have the same moral weight as abortion and euthanasia." Which means the issue of abortion and euthanasia is at the highest level of priority for morality, which was demonstrated in Archbishop Burke's letter. In fact it could be interpreted that the only way to outweigh abortion or safeguarding the right to life is if both candidates do not safeguard the right to life and as a result one must choose the candidate who cooperates in moral evil the least. So the question becomes, what does proportionate reasoning really mean? Which candidate really cooperates in moral evil the least and shows evidence for supporting legislation that protects life more often than the other candidate.
Troy