This is not the case. He is not denying her from mass, he is stating that until she publicly repents and goes to confession, she should be denied the Eucharist.Porteroso said:
This is a Catholic denying a person communion with God. You or I can disagree on whether you need a priest to commune with God or not, but that's irrelevant.
This didn't decision was not a rash jump to judgement. The Archbishop has met with NP and discussed the abortion topic several times. When he took office in SF, he began praying for her conversion on this issue. He has attempted to reach out to her again (after comments after the leak) and she has will not respond to him.
Per Canon Law, can. 383, 1, he not only has the right, but also the responsibility to be "concerned for all the Christian faithful entrusted to his care" which is the archdiocese of SF, Pelosi's home diocese.
The Archbishop stated in the Notification that her public stance on abortion
"those who are directly involved in lawmaking bodies have a 'grave and clear obligation to oppose' any law that attacks human life. For them, as for every Catholic, it is impossible to promote such laws or to vote for them" (cf. Doctrinal Note on some questions regarding the participation of Catholics in political life [November 24, 2002], n. 4, 1). A Catholic legislator who supports procured abortion, after knowing the teaching of the Church, commits a manifestly grave sin which is a cause of most serious scandal to others. Therefore, universal Church law provides that such persons "are not to be admitted to Holy Communion" (Code of Canon Law, can. 915)."
Since the Last Supper, confirmed in Acts and practiced for the last 2000 years, the Eucharist is the actual body, blood, soul, and divinity of Jesus Christ.
Receiving the Eucharist in the state of mortal sin in also committed another mortal sin and potentially disastrous for one's soul.
1 Corinthians 11:27, 29-30:
27 Whoever, therefore, eats the bread or drinks the cup of the Lord in an unworthy manner (in the state of mortal sin) will be guilty of profaning the body and blood of the Lord. 29 For any one who eats and drinks without discerning the body eats and drinks judgment upon himself. 30 That is why many of you are weak and ill, and some have died.