Disclaimer: I know this is a controversial post. I am not looking to begin a debate about any of the issues. I am simply compiling these links and excerpts within to present the facts to my daughter, who is at the aqe (17) where she needs to think more deeply on these things. The conscience of a Catholic is between him/her and God. However, as a Catholic parent it is my duty to help form my children’s consciences. However they use their consciences when the time comes is up to them. I will not be in the voting booth.

Worthiness to Receive Holy Communion — General Principles
by Cardinal Joseph Ratzinger

Important points:

From #1. The practice of indiscriminately presenting oneself to receive Holy Communion, merely as a consequence of being present at Mass, is an abuse that must be corrected.

Reverence for the Eucharist is paramount. This is Jesus that we receive at the altar. It is not some wafer that we partake of without looking at our worthiness to do so. We should be coming to the altar with clean hearts and clean souls, knowing that we are in full communion with Christ and His Church.

From #2. 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.

This answers your question about some of your friends’ beliefs, Ais. We can respect and tolerate everyone’s beliefs. We do not have the right to force our opinions on them. But that doesn’t mean we express this respect and tolerance by going against what is the very grain of OUR belief. We cannot vote based on respect for someone else’s concept of freedom.

Everyone has the right to drive a car, provided they’ve got a license. That doesn’t mean we should all be free to run over people anytime we want to. With freedom comes responsibility. True freedom only comes when we operate within the rules. Freedom on the highway doesn’t mean you can drive any direction at any speed you choose. Freedom means following the rules, making it safe for everyone and not just a select few.

From #3. 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.

Dad and I don’t agree on the war. He doesn’t agree with the Pope 100% on this matter, but that doesn’t make Daddy a bad Catholic. However, on the issue of abortion, we do not (cannot, will not) go against the teachings of the Church. The Church is unequivocal about abortion and euthanasia being an EVIL, and rightly so. God giveth and God taketh away. We have no right to put an ending to what the Author of Life has penned. It is not our story to tell.

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.

Now you get to compare Obama and McCain’s voting record. (pdf file)

We were talking about the “lesser of two evils” question. Here’s an excerpt from another LifeSite article (Can Catholics Who Vote for Obama Still Receive Communion?) that speaks to this:

As Bishop Rene Henry Gracida, of Corpus Christi Texas, explained in September 2004: “Consider the case of a Catholic voter who must choose between three candidates: Kerry, who is completely for abortion on demand, Bush, who is in favor of very limited abortion, i.e., in favor of greatly restricting abortion and Peroutka, a candidate who is completely against abortion but who is universally recognized as being unelectable. The Catholic can vote for Peroutka, but that will probably only help ensure the election of Kerry. Therefore the Catholic voter has a proportionate reason to vote for Bush, since his vote might help to ensure the defeat of Kerry and might result in the saving of some innocent human lives.”

I think the answer is quite clear.

Additional info:

Something that may be useful to you if you decide to write a paper on Planned Parenthood and Margaret Sanger: Margaret Sanger would have loved Barack Obama by Clenard Childress (a non-Catholic, BTW)

And an article that tackles why some Catholics support Obama: Roman Catholics for Obama ’08 by Paul Kengor

Lastly, don’t forget this: Obama’s Abortion Bombshell: Unrestricted Abortion Over Wishes of Individual States a Priority for Presidency

09/21/08, Edited to add:
Is it a sin to vote?