The Supreme Court will hear two cases related to gay marriage starting Tuesday.

On Tuesday, the justices will consider a challenge to Proposition 8, a constitutional amendment approved by California voters in 2008 which defines marriage as a heterosexual union.

The following day, Wednesday, the court will hear oral arguments in a case involving the Defense of Marriage Act (DOMA). DOMA was approved by Congress and signed into law by President Bill Clinton in 1996. Because of DOMA, the government is prevented from recognizing the legal marriages of gay and lesbian couples. Gay couples can currently marry in 9 states plus the District of Columbia. An additional 11 nations have legalized such unions.

Doug NeJaime, a professor who teaches Family Law & Sexuality at Loyola Law School, wrote in anticipation of this week's arguments.

“This week the Court will hear arguments in two key cases involving same-sex marriage: Hollingsworth v. Perry, the challenge to California's Proposition 8, which eliminated same-sex couples' right to marry; and United States v. Windsor, the challenge to Section 3 of the Defense of Marriage Act (DOMA), which denies federal recognition to same-sex couples' valid state law marriages. The Justices' arguments may reveal not only whether they are likely to rule on the merits, but how exactly they are thinking about those merits. In Windsor, the Justices may take up the Second Circuit’s conclusion that classifications based on sexual orientation should be subjected to heightened scrutiny under the Equal Protection Clause. If so, they will likely probe issues regarding the history of discrimination against lesbians and gay men and the political power of the groups. Regardless of the level of scrutiny the Court ultimately applies, even some of the more conservative Justices may be bothered by DOMA's unique federal intervention into state policy. In Perry, the Justices' questions and comments may not only suggest whether a majority believes Proposition 8 to be unconstitutional but how far such a ruling might extend. Some Justices may be interested in limiting the case to the specifics of California while others may prefer a broader decision that impacts marriage bans across the country. Still others may find a middle road, analyzing laws that provide the substantive rights and benefits of marriage under a nonmarital designation.”

Appearing on CNN, legal analyst Jeffrey Toobin argued that both cases break down to one simple argument: “Can the government in giving out benefits – whether it's taxes, whether it's marriage, whether it's child custody – can the government say gay people get one set of benefits and straight people get another? Can gay people get less?”

The court is expected to hand down a ruling in June.