A multi-part post, as I have to give my reasoning, and URLs.
Must Catholics deny Transsexuals and the Intersexed Human Rights?
The Magisterium has not said so.
The Congress of American Catholic Bishops has not said so.
The Pope has said so though.
First, to show that the Vatican thinks it would be best to legally deny gays human rights:
The Vatican expressed similar concerns in a 1992 letter to Bishops of the Catholic Church – authored by then-Cardinal Ratzinger, now Pope Benedict XVI – regarding legislation to “make discrimination on the basis of sexual orientation illegal,” which according to Ratzinger, “may in fact have a negative impact on the family and society.”
“Even when the practice of homosexuality may seriously threaten the lives and well-being of a large number of people, its advocates remain undeterred and refuse to consider the magnitude of the risks involved,” Cardinal Ratzinger wrote. “’Sexual orientation’ does not constitute a quality comparable to race, ethnic background, etc., in respect to non-discrimination. Unlike these, homosexual orientation is an objective disorder and evokes moral concern.”
“Including ‘homosexual orientation’ among the considerations on the basis of which it is illegal to discriminate,” Ratzinger wrote, “can easily lead to regarding homosexuality as a positive source of human rights…(and)…to the legislative protection and promotion of homosexuality.”
What Human Rights are we talking about here? Let's look at the list of rights in the legislation ynder consideration that is deemed to have a "negative impact on the family and society".
To be allowed to use:
(1) restaurants, soda fountains, and other eating or drinking places, and all places where food is sold for consumption either on or off the premises;
(2) inns, hotels, and motels, whether serving temporary or permanent patrons;
(3) retail stores and service establishments;
(4) hospitals and clinics;
(5) motion picture, stage, and other theaters and music, concert, or meeting halls;
(6) circuses, exhibitions, skating rinks, sports arenas and fields, amusement or recreation parks, picnic grounds, fairs, bowling alleys, golf courses,
gymnasiums, shooting galleries, billiard and pool rooms, and swimming pools;
(7) public conveyances, such as automobiles, buses, taxicabs, trolleys, trains, limousines, boats, airplanes, and bicycles;
(8) utilities, such as water and sewer service, electricity, telephone, and cable television;
(9) streets, roads, sidewalks, other public rights-of-way, parking lots or garages, marinas, airports, and hangars; and
(10) places of public assembly and entertainment of every kind.
That from Bill 23-07 in Maryland, and opposed by the Thomas More Legal Centre.
While these do not in themselves appear to be especially dangerous, the danger is that by supporting the granting of any such rights, the church will be seen to be tolerating homosexuality. That is such a bad outcome that catholics must actively oppose such measures, by whatever means necessary. I'll talk about the means later, and give justification for my statement there.
The argument against Homosexuality has since been expanded, as being against Natural Law. Why is it against Natural Law? Because it causes confusion between the two God-ordained sexes, and anything which does that is dangerous to humanity's survival. There is a Human ecology, just as there is a Global ecology, and this must be protected against such threats to the Natural Order. Anything that confuses the sexes is dangerous, and must be legally suppressed. Well-intentioned laws granting or maintaining existing human rights for anyone who confuses the sexes are thus dangerous - and so presumably should be opposed.
About Natural Law, and the danger to human survival of Intersex - things between male and female - and a call to speak up on this issue:
(The Church) must also protect man from self-destruction. What is needed is something like a human ecology, correctly understood.
If the Church speaks of the nature of the human being as man and woman, and demands that this order of creation be respected, this is not some antiquated metaphysics. What is involved here is faith in the Creator and a readiness to listen to the “language” of creation. To disregard this would be the self-destruction of man himself, and hence the destruction of God’s own work.
To carry our reflection further, we must remember that the problem of the environment is complex; one might compare it to a multifaceted prism. Creatures differ from one another and can be protected, or endangered, in different ways, as we know from daily experience. One such attack comes from laws or proposals which, in the name of fighting discrimination, strike at the biological basis of the difference between the sexes. I am thinking, for example, of certain countries in Europe or North and South America.