A Letter to the Speaker
Like you, I went to Catholic college (Loras College, 1984) and took Ethics Class (I was pre-law, so it was required). When we discussed protecting innocent life, we asked the professor about whether life began at conception. In context, he was hardly a Vatican II left-winger (the school was a minor seminary, so he could not be). What he said was that, because of twinning, life could not begin until 8 days after conception. Before that point, there is no uncertainty so it need not be protected under Aristotelean ethics. The principle is, if there is doubt, an individual must not act to put life at risk. (By the way, Genetics texts agree that Gastrulation, which occurs after implantation, is the real begining of life, as it is the first point where the genes of both parents control the development of the child - before that you can slice and dice a blastocyst to get multiple children and you can have a non-human to human hybrid grow and develop).
This principle may absolutely be extended to the question of birth control, but cannot be used on the abortion issue. Under Aristotelian ethics, where the higher rules the lower, ensoulment likely occurs at gastrulation as the soul guides the development of the body. As a Catholic and an individual (but not as Speaker) you must believe in the existence of a dualistic soul - which is why the Bishops are so hot on the issue, as if the soul is developmental (meaning its existence is tied to the development of the brain) then there is really no such thing as an immortal soul. This puts the whole question of religion at risk, so they cannot budge on the abortion question.
As Speaker, you have a different set of responsibilities - the development of sound law and public policy. I campaigned for Jim Moran to get you as Speaker, so I trust your judgment, including your judgement on morals. I would suspect that part of your well formed Catholic conscience includes protecting women from back alley and self-induced abortions. It likely also includes protecting the constitutional order - especially federal supremacy on civil rights law (which overturning Roe would put at risk).
As a mushy middle Catholic, who dislikes abortion, does not consider it a civil right or a boon to women BUT who also disagrees with the bad public policy of making abortion illegal or even giving civil rights to the unborn prior to the development of the lungs, I urge you to be up front in defending the pro-choice position, or rather attacking the pro-life position, rather than falling back on any moral doubt about the status of the fetus (there isn't one) or any desire not to impose your will on non-Catholics (as I elected Moran and by extension you to impose your will on such issues as tax policy and the war in Iraq).
I have more on this, including quite a bit on my blog at xianleft.blogspot.com.