Is California’s Proposition 8 constitutional? Prop. 8 amended the state’s constitution to ban same-sex marriages. With the justices set to hear arguments Tuesday on Prop. 8, following are excerpts of views from bloggers, columnists, proponents and opponents of the law:

Cato Institute and Constitutional Accountability Center, amicus brief to the U.S. Supreme Court (Hollingsworth v. Perry): “The text of the equal protection clause of the Fourteenth Amendment is sweeping and universal: ‘No State shall . . . deny to any person within its jurisdiction the equal protection of the laws.’ … Drafted in 1866 and ratified in 1868, the clause wrote into the Constitution the ideal of equality first laid out in the Declaration of Independence, establishing a broad guarantee of equality for all persons and demanding ‘the extension of constitutional rights and protections to people once ignored or excluded.’ … The Constitution also protects fundamental rights under the substantive liberty provisions of the 14th Amendment. This court’s [U.S. Supreme Court] cases protecting the equal right to marry have been rooted in both the equal protection clause’s guarantee of equality under the law and equality of rights and the 14th Amendment’s protection for substantive liberty. … The text and history of the equal protection clause make clear that Prop. 8 unconstitutionally denies the equal protection of the laws regarding marriage to same-sex couples, who are unquestionably included within the scope of the equal protection clause, and perpetrates an impermissible injury to these couples’ personal dignity.”

Family Research Council, amicus brief to the U.S. Supreme Court (Hollingsworth v. Perry): “ … the fundamental right to marry that has been recognized by this court is limited, by the nature of marriage itself, to opposite-sex couples. None of the court’s precedents supports a right to enter into a same-sex marriage and, with the exception of the district court’s holding and the decision of the California Supreme Court, which was overturned by Proposition 8, no state or federal court has held otherwise. Reserving marriage to opposite-sex couples does not violate the fundamental right to marry protected by the due process clause. … Proposition 8 treats men and women the same. Both may marry someone of the opposite sex; neither may marry someone of the same sex. With the exception of the district court’s judgment in this case and a two-judge plurality opinion of the Hawaii Supreme Court, no state or federal court has accepted plaintiffs’ sex discrimination argument. Proposition 8 does not violate the equal protection clause. … No state or federal court applying federal equal protection analysis has held that classifications based upon one’s sexual orientation are subject to heightened review. Because Proposition 8 is reasonably related to multiple, legitimate state interests, it passes constitutional muster.”

John C. Eastman, The Heritage Foundation: “Cultural institutions are fragile things. Marriage, as the more or less permanent union of one man and one woman, developed in large part to encourage the procreative relationship that is necessary for the perpetuation of society.

“No one knows the extent to which redefining marriage so substantially as to include relationships that are biologically not connected to that societal purpose will undermine the institution itself.

Some of the evidence introduced at trial in the Hollingsworth case is not encouraging. As feminist professor Ellen Willis admitted, redefining marriage to encompass same-sex relationships ‘will introduce an implicit revolt against the institution into its very heart.’ That revolt is, as Johns Hopkins University Professor of Sociology Andrew Cherlin explains, ‘the most recent development in the deinstitutionalization of marriage,’ the ‘weakening of the social norms that define people’s behavior in … marriage.’ In other words, the redefinition of marriage to encompass homosexual relationships may well be an experiment of civilizational magnitude.”

Crosby Burns, Center for American Progress: “Opponents of gay rights have historically undermined equality and fairness for gay Americans by directly attacking gay people themselves. But as the public has become more accepting of gay individuals, this tactic has become less and less successful.

“For this reason, opponents of equality are hiding behind the guise of ‘religious liberty’ to perpetuate a discriminatory and unequal legal environment for gay people. The First Amendment guarantees the ability to practice one’s religion free from government interference. It allows Americans to worship freely and bring their faith into the public square.

“But the cases … are not about religious liberty in the slightest. They are about people using religion to discriminate, and that should not be allowed to stand.”

Frank Bruni, The New York Times: “But the legalization of same-sex marriage takes nothing from anyone, other than the illusion, which is all it is and ever was, that healthy, nurturing relationships are reserved for people of opposite sexes. … the court could, in its ruling on the constitutionality of a California ban against same-sex marriage, hasten the spread of marriage equality beyond those nine states and the District of Columbia.

“For now the count builds slowly, through time-consuming, patience-fraying, expensive legislative and referendum battles, and a matter of basic fairness is beholden to local politics and pockets of enduring bigotry. But fairness is where we’re heading, at least in regard to marriage, which has emerged as the terrain on which Americans are hashing out their feelings about gays and lesbians. The trajectory is undeniable. The trend line is clear. And the choice before the justices is whether to be handmaidens to history, or whether to sit it out.”

Editor’s note: The Supreme Court has scheduled arguments Wednesday in a challenge to a federal bar to same-sex marriage: the Defense of Marriage Act.