From Lifesite, via Amy:
Bp. Rene Gracida (retired, Corpus Christi) reveals his efforts to dissuade a "pro-choice Catholic" politician from his errors. After the politician gave no response to the bishop's letters of correction and warning, Bp. Gracida applied the penalty of "interdict", which forbids the offender from receiving the sacraments of the Eucharist or Anointing of the Sick.
If I understand aright, this is close to the approach Pete has recommended, and I can see why: the letters of instruction, the warnings, and even the choice of interdict rather than excommunication help to show that the bishop's aim is to dissuade, correct, and reform the erring Catholic, and not to 'expel' him from the Church. The bishop even goes so far as to keep the process private between himself and the dissenter, unless he finds that the latter disregards the penalty and insists on receiving the Eucharist.
Sad to say, the politician in this case died in 2001, apparently without recanting his errors. And what gain did his worldly-minded supporters give him in reward for his stubbornness? The power and privilege of being a member of the state legislature: which is to say, not much.
Thank you, Bp. Gracida, for your efforts to correct a sinner and defend the sacredness of human life and of the Most Holy Sacrament. May the Lord always keep us (or make us, to the extent that we are not) faithful to His Gospel.
Update: I previous had Bp. Gracida's title wrong, but have fixed it now.