Before considering the merits of DOMA, the court considered two threshold issues: whether it even has jurisdiction to hear the case given that the Obama administration believes DOMA should be overturned, and whether BLAG has legal "standing" to defend it. Both sides wanted the court to consider the merits of DOMA, so the court appointed Harvard law professor Vicki Jackson to argue the threshold issues.
On Tuesday, supporters and opponents of gay marriage gathered outside the Supreme Court to hold signs and make their voices heard. The justices struggled with the notion of extending marriage rights to gay couples, pressing lawyers on both sides of the Prop 8 case.
All eyes once again focused on Justice Kennedy, viewed as the court's key swing vote on gay marriage.
On Tuesday, he asked some conflicting questions on the issue of the lawyers arguing before him.
"The voice of these children is important," Kennedy said at one point, noting that children of gay couples want their parents' unions to be recognized as marriages.
But later he told the lawyer for gay couples challenging the ban that the issue was in "uncharted waters."
The court was considering these two potentially landmark gay-marriage cases as the politics of the issue shift by the day.
After Ohio Republican Sen. Rob Portman announced his support for gay marriage earlier this month, becoming the only current GOP senator to hold that position, a herd of Democratic senators have stampeded toward the marriage issue. Sens. Claire McCaskill, D-Mo., Mark Warner, D-Va., Jon Tester, D-Mont., and Mark Begich, D-Alaska, have all announced their support for gay marriage this week.
Public opinion, too, has shifted drastically on gay marriage in the last decade.
A recent ABC News/Washington Post poll, taken March 7-10, showed 58 percent of respondents in support of gay marriage, while 36 percent opposed it. That's nearly the opposite of public opinion on gay marriage in 2003, when ABC/Post polling showed 37 percent support and 55 percent opposition.