I like E.J., Kathryn, but I thought the column was full of holes. I’ll try to give the short version of the critique.
1) It is not true that to be consistent, the bishops will have to deny communion not only to pro-abortion politicians but also to pro-life politicians who support pro-abortion colleagues. (I’ll leave out the complete argument as to why this is untrue, in the interests of succinctness–but you can get the gist of it here.) Dionne writes, “Why is it acceptable for a committed Catholic abortion opponent such as Santorum to support Specter over an antiabortion candidate, but not Kerry over Bush? Might Specter’s party label have something to do with it?” But nobody is asking for the bishops to condemn Catholics who support Kerry, or even to oppose his election. Let us imagine the impossible: that Santorum were to endorse Kerry this year. As far as I can tell, nothing being proposed today would give the bishops any call to deny him communion. Let us imagine another impossibility: that Santorum will start voting to to deny justice to the unborn. Then, under the standard that is actually being discussed, it would indeed be necessary to deny him communion. Party labels do not account for the substantive differences between these cases.
2) The article fails to take seriously the ideas that abortion is the unjust taking of human life, that to vote to allow abortion in the legislature is to perform an act of serious injustice, and that this act imperils the soul of the sinning legislator. Maybe Dionne does not subscribe to these ideas himself, but the Catholic church does. If he wants to give the bishops advice other than to ditch these premises, he needs to acknowledge their existence and force.