Giuliani wants it both ways, in classic Republican style. It is, in essence, the same hypocrisy as Vitter, Craig, Allen, Foley, etal. Pretend to be someone you are not to get votes and win elections.
Giuliani wants to fool voters into believing he is a practicing Catholic in good standing with the church when he is not. Wayne Barrett, again, has the real story on Rudy's religiosity:
Giuliani has invoked his Catholic heritage on Larry King; he's been described by The Washington Post as a "devout Catholic"; he's appeared on Fox News with the label "Catholic" floating on-screen; and he's handled a CNN debate question about a bishop who denounced him with a declaration unfamiliar to those who covered him as mayor. "I respect the opinion of Catholic and religious leaders of all kinds," he said. "Religion is very important to me. It's a very important part of my life."
Married three times, Giuliani simply isn't the Catholic candidate he claims to be. He can't have a confessor. He can't receive the sacraments of penance, the Eucharist, or marriage. While bishops disagree about whether or not a Catholic politician who supports abortion rights can receive the sacraments, there is no disagreement about the consequences of divorcing and remarrying outside the church, as Giuliani did a few years ago.
"Any Catholic who remarries without annulment" assumes an "irregular status" within the church, says Monsignor Joseph Giandurco, who until recently was the canon-law expert at the seminary run by the Archdiocese of New York. Also a judge on the appeals court of the archdiocese's marriage tribunal and a canon-law adviser to Cardinal Edward Egan, Giandurco declined to answer questions about Giuliani individually, but speaking in general terms about someone with Giuliani's marital history, Giandurco added: "The marriage is not recognized by the church, and the person cannot receive communion or confession. He's not supposed to play a public role in the church."