Supreme Court Hears Gay Marriage This Week Two potentially transformative cases about gay marriage will be argued at the Supreme Court this week. Justices have set aside two days to hear arguments and will release audio arguments the same day. Both cases will be decided by the end of June. Here's what you need to know about the legal cases: First up is a challenge to California's Proposition 8, the controversial ballot initiative that defines marriage as between a man and a woman. Although the court could rule more narrowly, this case asks the big question of whether there is a fundamental right to gay marriage. But there is a hurdle the justices must clear before they get to the merits of the case. The jurisdictional question: The original sponsors of Prop 8 -- a group called Protectmarriage.com -- are defending the law because California officials refused to do so. The Supreme Court will explore whether the proponents have the legal right to be in court. If the court finds that the original sponsors have no "standing," then the case comes to a screeching halt, and the court will not reach the merits of the case. "Although it may sometimes seem like a technicality, the Supreme Court wants to ensure that the federal courts only decide real, concrete disputes, brought by people that have been injured by the laws they want to challenge," said David Cruz, a professor of law at the University of Southern California Gould School of Law. Charles J. Cooper, a lawyer representing Protectmarriage.com, argues in court papers that the California Supreme Court gave the sponsors the state's authority to defend the law and the U.S. Supreme Court should respect that in the case of Hollingsworth v. Perry. Opponents of Prop 8 argue that "standing" requires an injury and proponents of Prop 8 cannot show they will be harmed if same-sex couples marry. "Proponents have never contended -- and do not contend before this Court -- that they would personally suffer any injury if gay men and lesbians were permitted to marry in California," write lawyers Theodore B. Olson and David Boies on behalf of gay couples who are challenging Prop 8. Olson and Boies argue that if the court finds that proponents have no standing, then gay marriages should be able to resume in California. The merits: The central thrust of Cooper's arguments on the merits is that Californians who voted in favor of Prop 8 opted "in good faith" to preserve the traditional definition of marriage because they believe it continues to meaningfully serve important societal interests. "In order to win, Cooper has to convince the court that there is a legitimate justification for Prop 8, that doesn't depend on hostility toward gay people," Cruz said. Specifically, Cooper argues, marriage is "inextricably linked to the objective biological fact that opposite-sex couples and only such couples are capable of creating new life together and, therefore, are capable of furthering, or threatening, society's existential interests in responsible procreation and childbearing." Cooper says that while marriage may serve "additional purposes" as long as "responsible procreation remains one of the purposes of marriage," plaintiffs cannot prevail. He says that Prop 8 leaves undisturbed expansive domestic partnership laws that provide gays and lesbians with "some of the most comprehensive civil rights protections in the nation." Cooper says the court should defer to the democratic process. "[t]he definition of marriage has always been understood to be the virtually exclusive province of the states, which, subject only to clear constitutional constraints, have absolute right to prescribe the conditions upon which the marriage relation between their citizens shall be created. " He says the lower court decision striking down the law "impugns the motives of over seven million California voters and countless other Americans who believe that traditional marriage continues to serve society's vital interests." Olson and Boies respond in sweeping arguments that ask the court to find a fundamental right to gay marriage in the Constitution. "The unmistakable purpose and effect of Proposition 8," they write, "is to stigmatize gay men and lesbians -- and them alone -- and enshrine in California's Constitution that they are unequal to everyone else, that their committed relationships are ineligible for the designation 'marriage' and that they are unworthy of that most important relation in life." Opponents of Prop 8 dismiss the proponents' argument that Proposition 8 serves the interest of promoting responsible procreation. There are many classes of heterosexual persons who cannot procreate unintentionally, including the old, the infertile, and the incarcerated. They acknowledge that the federal system enables states to serve as "laboratories of democracy" but say "our Constitution does not permit states the power to experiment with the fundamental liberties of citizens." Because the U.S. government has never been a party to the Prop 8 case, it did not have to weigh in on the case now that it is in front of the Supreme Court. But last month Solicitor General Donald B. Verrilli Jr. filed a brief with the court opposing Proposition 8, arguing that laws that ban gay marriage should be subject to heightened scrutiny from the courts. The court has allotted one hour for arguments in the case, although because of the complexity of the issue, arguments could be extended. Charles J. Cooper will argue for petitioners. Theodore B. Olson will argue for respondents; Solicitor General Donald B. Verrilli Jr. for the government.