Listen to key moments from the courtroom

Several justices, including Chief Justice John G. Roberts, sounded skeptical Tuesday that Dennis Hollingsworth, a private citizen who led the group sponsoring the Prop. 8 ballot measure, could defend the state’s laws. “I don’t think we have ever allowed something like that,” Roberts said.

Justice Kennedy, while acknowledging that the long-term effects of legalized gay marriage are unknown, suggested that the tens of thousands of children of gay and lesbian couples in California have a voice in the case as well. “They want their parents to have full recognition,” he said.

Justice Elena Kagan drew laughter in the courtroom when she pressed attorney Charles Cooper to explain why the government should deny marriage to same-sex couples. Cooper, who represents the sponsor of Prop. 8, said marriage was about “responsible procreation.”

If Kennedy made clear his sympathy to gay marriage in California, Chief Justice John G. Roberts and conservative colleagues were just as clear in saying they opposed the idea. Marriage has been limited to a man and a woman since “time immemorial,” Roberts said.

In an exchange with Chief Justice Roberts, Attorney Ted Olson contended that the label of marriage was just as important as the state recognition that comes with it. “It is like you were to say ‘You can vote, you can travel, but you may not be a citizen,’” Olson said.

Twice during the oral argument, Kennedy questioned why the court had voted to hear the California case. “I wonder if this case was properly granted,” Kennedy said.

Attorney Charles Cooper said that allowing same-sex marriage could potentially harm marriage as an institution. “Among those real world consequences, Your Honor, we would suggest are adverse consequences.”

Justice Alito stressed the need for caution going forward, citing the lack of data on same-sex marriage. “You want us to step in and render a decision based on an assessment of the effects of this institution which is newer than cell phones or the Internet?”

Listen to key moments from the DOMA hearing