A pep rally of sorts took place throughout the morning for those on both sides who care deeply about the outcome of this landmark case. But inside, there were no arcane arguments; the justices had hard hitting questions for the critics and supporters of Proposition 8, California's ban on same-sex marriage.
"You have reasons for not including same sex couples, do you have any reason for excluding them," Justice Elena Kagan asked.
"There are some 40,000 children in California with same-sex parents and they want their parents to have full recognition and full status," Justice Anthony Kennedy said. "The voice of the children should matter, don't you think?"
"When did it become unconstitutional to exclude homosexual couples from marriage," Justice Antonin Scalia asked. "1791? 1868?"
Besides the merits of the case, the justices must also decide if Prop 8's backers even have the right to be in court, since the state is not defending the voter approved ban.
Sacramento's Andy Pugnio says absolutely.
"If it's determined that the initiative can be vetoed by government officials, that would be a fatal blow to the initiative process," Pugnio said.
Plaintiffs Kris Perry and Sandy Stier brought their 18-year-old twin sons and say they just want to be treated equally.
"In this country as children we are taught there's a founding principal that all men and women are created equally and we want that equality," Perry said.
Perry and Stier of Berkeley and Paul Katami and Jeff Zarrillo of Burbank, filed their federal lawsuit in May 2009 to overturn Prop 8, which voters approved the previous November. The ballot measure halted same-sex unions in California, which began in June 2008 after a ruling from the California Supreme Court.
Roughly 18,000 couples were wed in the nearly five months that same-sex marriage was legal and those marriages remain valid in California.
Wednesday, the justices will hear arguments on the constitutionality of the Defense of Marriage Act, the federal law that prevents legally married same-sex couples from getting federal benefits and privileges.
ABC7 News Reporter Carolyn Tyler is the Supreme Court for the Prop 8 and DOMA cases. Watch her live reports on ABC7 News and follow her on Twitter.