Conservative Justices Scalia, Alito and Roberts were "very hostile to the idea of the court imposing same sex marriage," according to Toobin. The four Democratic justices seemed favorably disposed.
Justice Kennedy seemed like he was in the middle, he said things that would "give comfort for both sides," Toobin says. Kennedy suggested the issue was brought prematurely before the court.
[Updated at 11:37 a.m. ET]
The justices seemed very focused on how Prop 8 affects children, with Justice Kagan at some point suggesting that California have a law allowing same-sex marriage for people past child-bearing age, Toobin said.
Kagan said, according to Toobin: "I assure you if two 55 year old people, there aren't a lot of children (coming from that marriage)."
[Updated at 11:34 a.m. ET]
"This was a deeply divided Supreme Court, a court that seemed groping for answers," CNN senior legal analyst Jeffrey Toobin said after watching the arguments. "Now I think its even harder to predict the result of this case after hearing this argument."
[Updated at 11:31 a.m. ET]
Oral arguments have wrapped up, according to CNN Supreme Court producer Bill Mears. They went just a bit over schedule, lasting about one hour and 20 minutes.
[Updated at 11:23 a.m. ET]
While we wait on word from the courthouse, consider this: A new CNN/ORC International Poll indicates that 53% of Americans support same-sex marriage. In the same survey, 57% of respondents said they had a family member or close friend who is gay or lesbian.
[Updated at 11:06 a.m. ET]
The same-sex marriage debate is a huge issue, and the lawyers inside were penciled in for an hour to make their cases. Doesn't sound like much time, but to be fair, the oral arguments regarding the Affordable Care Act (aka "Obamacare") last March lasted roughly two hours.
Tomorrow's DOMA arguments have been given one hour and 50 minutes. We'll see if they stay on schedule today.
[Updated at 10:46 a.m. ET]
If all is going to plan, Jean Podrasky, a lesbian whose first cousin happens to be Chief Justice John Roberts, is inside the court hearing the arguments.
"I know that my cousin is a good man," she wrote in an op-ed this week. "I feel confident that John is wise enough to see that society is becoming more accepting of the humanity of same-sex couples and the simple truth that we deserve to be treated with dignity, respect, and equality under the law."
You might see a lot of red avatars with a "=" equal sign in your Twitter feed today. Supporters of marriage rights for same-sex couples are wearing red today to show their support -- both on their persons and their social media accounts. That includes Maryland Gov. Martin O'Malley.
[Updated at 10:39 a.m. ET] You can find a reminder of who's who among the nine justices here.
Try clicking on each photo to learn more about the men and women who will decide the legal fate of same-sex marriage (for now anyway) -- see where they were born and educated, their career highlights and their religion.
[Updated at 10:30 a.m. ET]
Inside, we expect Republican Ted Olson and Democrat David Boies joining forces in pushing for legal recognition of same-sex marriage. Prominent Washington attorney Charles Cooper will lead the defense of Proposition 8, the California referendum against same-sex marriage.
Fun fact: Olson and Boies argued opposite sides of the landmark 2000 Bush v. Gore case, which decided that presidential election.
[Updated at 10:23 a.m. ET]
The temperature is rising a bit and so is the volume. Thousands have amassed in front of the U.S. Supreme court as the morning warms up.