Political party affiliation is not necessarily an endorsement of being pro-life or pro-abortion. Groups like “Democrats For Life” exist and there are pro-life Democrats in Congress.
Conversely, there are pro-abortion Republicans-- including front-runners like Rudy Guiliani. There are many Republicans who do not have a pro-life ethos even though their party claims to. And, what is more, the Republican party, who has had both houses of Congress AND the Presidency for 6 years has done NOTHING to help the pro-life cause. They could have done many MAJOR things, including pushing through the Human Life Amendment or legislation declaring life begins at conception-- but NO, they haven’t done a thing.
Excommunication is the last step in an juridic process-- review Canon Law for the specifics. It is meant to be a last resort, and the expectation is that it is so serious it will cause the person to repent and be reconciled to the Church.
The current climate of moral relativism, I believe, makes this once powerful tool of the church less relevant to todays dissenters and heretics. They don’t recognize or believe that excommunication condemns them.
Bishop Bruscowitz excommunicated several groups almost 20 years ago-- and those groups are still fighting it within the judicial system of the Catholic Church. They are not one bit repentant or remorseful and have made no steps to be reconciled to the Church. They also continue, business as usual, and call themselves Catholics.
Protestant denominations have fared no better-- a large group of Protestant denominations now themselves embrace abortion, advocate for it, and support abortion politicians.
Protestantism is far from the pure, united pro-life powerhouse.
A pro-abortion Catholic is an example of dissent and heresy and personal sin.
A Protestant pro-abortion person, on the other hand, can actually be endorsing their denomination stand on abortion.