I wish our bishops and priests would step up to the plate and follow this example. In fact, it is their obligation to do so, because the Vatican has spoken clearly on this matter several times in the last few years. The most explicit document was a letter written by Cardinal Ratzinger in 2004, a year before he became Pope. It's a short letter but very rich in teaching about a number of important issues. Paragraphs 5 and 6 are so explicit on this issue that even a child would grasp them:
5. Regarding the grave sin of abortion or euthanasia, when a person’s formal cooperation becomes manifest (understood, in the case of a Catholic politician, as his consistently campaigning and voting for permissive abortion and euthanasia laws), his Pastor should meet with him, instructing him about the Church’s teaching, informing him that he is not to present himself for Holy Communion until he brings to an end the objective situation of sin, and warning him that he will otherwise be denied the Eucharist.
6. When "these precautionary measures have not had their effect or in which they were not possible," and the person in question, with obstinate persistence, still presents himself to receive
the Holy Eucharist, "the minister of Holy Communion must refuse to distribute it" (cf. Pontifical Council for Legislative Texts Declaration "Holy Communion and Divorced, Civilly Remarried Catholics" [2002], nos. 3-4). This decision, properly speaking, is not a sanction or a penalty. Nor is the minister of Holy Communion passing judgment on the person’s subjective guilt, but rather is reacting to the person’s public unworthiness to receive Holy Communion due to an objective situation of sin.
That's not a typo: a priest or bishop has the authority and obligation to deny communion to an unworthy recipient. It's not an option. These ain't potato chips that he's handing out. It is Christ Himself. Any priest out there who doesn't comply is committing a direct act of disobedience to the Vatican.
So for the priests who read this: are you following orders? Why not? Are you chicken? That's not a valid reason. There is no valid reason to disobey. Fall into rank now.
Do it for Jesus in the Most Holy Sacrament.
Do it for the sake of the unrepentant communicant who needs to realize that his/her life is not in accordance with the Gospel.
Do it for the sake of setting a good example for your parishioners of obedience and reverence for the Eucharist.
Do it for the salvation of your own soul. Never lose sight of these words from Scripture:
Ezekiel 33,7-9: "Son of man, I have appointed you as sentry to the House of Israel. When you hear a word from my mouth, warn them in my name. If I say to a wicked man: Wicked wretch, you are to die, and you do not speak to warn the wicked man to renounce his ways, then he shall die for his sin, but I will hold you responsible for his death. If, however, you do warn a wicked man to renounce his ways and repent, and he does not repent, then he shall die for his sin, but you yourself will have saved your life."
You can read about other statements from the Vatican here.