"Here's what we know about how the Supreme Court is going to rule on health care," says Ezra Klein at The Washington Post: "Nothing." But there is a consensus among court-watchers that Chief Justice John Roberts will write the fateful decision handed down on Thursday morning and that, whatever the outcome, it will be a big deal. The chief justice is a young 57, but "to a great extent, the decision will shape the way history views Roberts' stewardship of the high court," says Josh Gerstein at Politico. Will "Roberts' big moment" on Thursday really determine how the world remembers the Roberts Court?

Yes. This is Roberts' "defining moment": For better or worse, the ObamaCare ruling "will be forever remembered as coming from the Roberts Court," says The Hill in an editorial. Big cases like this typically define chief justices — Roe v. Wade for Warren Burger, for example, and Bush v. Gore for William Rehnquist — and no matter how many more terms Roberts serves, "it is hard to imagine that many of the rulings from the bench he leads will be more historic than this one."
"Player of the week: Chief Justice John Roberts"

It's too early to talk about his legacy: Sure, voting to uphold or kill such a major, far-reaching law will be remembered for a long time, law professor John Eastman tells Politico. And, especially if he strikes down ObamaCare, there's no question it will make the top paragraph of his encyclopedia entry. But "this guy's only in his 50s. He could run this thing out for 30 years," and "I suspect he'll see a lot of cases" in that time. We have no way of knowing whether he's just getting warmed up.
"John Roberts's big moment"

And the real ObamaCare decider is Kennedy: Roberts may write the big health-care opinion, says Noah Feldman at Bloomberg, but the man calling the shots is Justice Anthony Kennedy. If Kennedy sides with the liberals to uphold part or all of the law, Roberts may join him in a 6-3 majority for tactical and PR reasons. If Kennedy sides with the conservatives, Roberts will, too. As the court's recent liberal-leaning rulings against Arizona's immigration law and life imprisonment for juveniles shows, this is in many ways Kennedy's court.
"Justice Kennedy leans liberal — for now"