I'm very willing to listen to someone explain to me why I'm wrong about this, but I'm just uncomfortable with the idea of the clergy telling politicians how they are supposed to vote in Congress. Think about it; how would we feel if they started taking this stance with politicians who supported the war?
The Pope opposed using military force in Iraq; he did NOT oppose the War on Terror. In fact, he was silent when the US and allies begain bombing the Taliban.
I wouldn't like it if these bishops started calling for priests to stop giving Communion to politicians who supported the war, or if they started questioning the "Catholicism" of politicians who supported the war.
That's a slippery slope possibility that I share, as there are many bishops who vehemently oppose the death penalty.
However, bishops are not telling politicians how to vote. What they are doing is saying that taking a public stance against a doctrine of the Church is scandalous, and that those who do that cannot consider themselves to be part of the larger Catholic community.
The politician who votes pro-choice simply cannot claim membership in an organization that is not.
2) No Catholic is under any obligation to agree with the Pope about the invasion of Iraq. The Pope is entitled to his opinion; I am entitled to my opinion.
3) The Church's teaching on abortion--and the Church teaches that the STATE has the DUTY to prohibit abortion--is a teaching that goes back to the very beginning. It is not a "political" position. It is an unchangeable constant. It is dishonest politicians, like Kerry, who PRETEND that when the Church condemns MURDER, the Church is "meddling in politics."
Prudential judgements versus support for intrinsic evils. That's the dividing line.