Anthony Kennedy

Justice Kennedy's input is pivotal in this decision — his vote could determine the outcome — but he didn't show his hand during Tuesday's arguments. He directed tough questions to both sides. Kennedy seemed to share the concern of the court's conservative justices when he said marriage has been understood as one man and one woman for "millennia-plus time." But he also focused on the dignity of same-sex marriage, as he has in previous decisions.

"[The definition of marriage has been around for] millennia-plus time. ... It's very difficult for the court to say, 'We know better.'"



"Same-­sex couples say, 'Of course, we understand the nobility and the sacredness of the marriage. We know we can't procreate, but we want the other attributes of it in order to show that we, too, have a dignity that can be fulfilled.'"



"[The states] had some premise that only opposite-­sex couples can have a bonding with the child. ­That was very interesting, but it's just a wrong premise."