Rick Santorum's recent statement that marriage is a privilege rather than a right is wildly untrue. Perhaps he sleeps better at night believing that he is denying people a mere privilege rather than a right?
In 1967 the U.S. Supreme Court issued a ruling in Loving v. Virginia (388 U.S. 1) that overturned a ban on interracial marriage and pronounced marriage a "basic civil right." Other subsequent cases recognized marriage as a fundamental right. In striking down a gay marriage ban in 2008, the California Supreme Court called same-sex marriage a right in its argument that the government cannot deny one the fundamental right to marry simply on the basis of gender. Chief Justice Ronald M. George stated in the opinion:
Our state now recognizes that an individual's capacity to establish a loving and long-term committed relationship with another person and responsibly to care for and raise children does not depend upon the individual's sexual orientation. ... An individual's sexual orientation -- like a person's race or gender -- does not constitute a legitimate basis upon which to deny or withhold legal rights.
Supporting the right to do something does not mean one has to support the actual doing of that thing. I, for instance, support the legalization of marijuana, but I do not support smoking marijuana. I support the First Amendment right of the KKK to demonstrate, but I still condemn their ideology. I support the right of adults to drink alcohol to their heart's content (or to their liver's failure), but I do not support alcoholism. Is this hypocrisy? Of course not, because one should recognize that in a free society, believing in someone's right to do something does not mean you have to support what they are doing. The distinction is similar to recognizing the difference between personal beliefs and what should be public policy.
Why can't politicians like Santorum and Romney support the right to gay marriage without supporting gay marriage itself? As a religious Jew, I support the rights of gays to marry and receive all rights attendant to marriage. According to the literal dictates of biblical law, homosexuality, Red Lobster, pork, and interfaith marriage between a gentile and a Jewish person are forbidden, but no one would oppose a person's right to engage in any of those activities.
Nevertheless, many religious organizations and politicians single out gay marriage as an exception. None of these organizations or politicians would support a ban on interfaith marriage or the use of condoms, or lobby for legislation forbidding people to eat at Red Lobster, despite these activities being forbidden according to a strict interpretation of biblical law. Atheism is also as much against their religion as homosexuality is. These organizations and politicians would not oppose the constitution's No Religious Test Clause, which states that "no religious test shall ever be required as a qualification to any office or public trust under the United States," despite the biblical prohibition against atheism. They should not oppose gay marriage, either, despite the arguable biblical prohibition against it.
Religious people and politicians who oppose gay marriage on religious grounds are making a huge mistake by failing to recognize the distinction between supporting someone's right to do something and supporting the act itself, and they are hypocritically attempting to impose a cherry-picked biblical law regarding homosexuality on the rest of society.
Whom someone wants to have sex with, and, according to the recent trend of jurisprudence and legislation, the sex of the person they want to marry, has no bearing on the constitutional right to marry, even if certain religious organizations and political parties do not support those personal choices. Religious people and politicians should be comfortable supporting same-sex marriage equality rights without having to personally support the union itself or downplaying the notion of marriage as a mere privilege.