The first day of October meant opening day at the Supreme Court. But Monday was strikingly different, as recently appointed Chief Justice John Roberts sat among his new colleagues. NewsHour regular Jan Crawford Greenburg talks about Roberts' first day on the job and the term ahead.

RAY SUAREZ: The first Monday in October is the traditional start of the new Supreme Court session. And today was particularly significant, because the court had a new chief justice, John Roberts. NewsHour regular Jan Crawford Greenburg of the Chicago Tribune was in the court and joins us now.

RAY SUAREZ: Did the seating of a new chief make this really different from a regular first day of the new court year?

JAN CRAWFORD GREENBURG: Oh, completely. Well, first of all there were two different events at the court today. Before the arguments began this morning, before Chief Justice Roberts took control of the court, there was a very formal swearing in ceremony -- about 9:15, just a little over an hour after President Bush announced he was nominating Harriet Miers. And that was a very formal ceremony. And the courtroom was packed with invited guests, friends, family, dignitaries, senators, judges who served on the D.C.-based federal appeals court bench with then-Judge Roberts. And it was a very moving ceremony just freighted with historic meaning.

Roberts came in the courtroom wearing the black robes, and sat in a black leather chair that had been used by the great Chief Justice Marshall centuries ago and he sat there as Attorney General Alberto Gonzalez announced he had the commission. The clerk read the commission in which the president nominated him as chief justice. And then he walked up behind the bench, and stood as Justice John Paul Stevens, the most senior member, formally swore him in as the new chief justice.

RAY SUAREZ: Beyond taking the oath did he have any remarks to make at that time?

JAN CRAWFORD GREENBURG: No, not at that moment. And about an hour later all the justices came back and took their seats again to start the new term and hear arguments. And even then, Justice Stevens got the first word. And he made an announcement that they were here, noting that the flags had flown at half-mast for the last month in honor of William Rehnquist, the chief justice, but today was a new day. And today they looked to the future and welcomed their new colleague. And then he noted -- and this caused all the justices to laugh -- that they knew John Roberts. That he had argued 39 cases before the court which was more than the combined experience of the rest of them.

So Justice Stevens said Roberts was coming on as someone they already knew and respected. And then at that moment, Chief Justice Roberts stepped forward, took over and welcomed some British lawyers who were visiting. Started swearing in lawyers to the Supreme Court bar and heard arguments of the first case. It was very much business as usual. And he was very much in control.

RAY SUAREZ: So plunging right in to today's arguments, was he a big player in the give-and-take with the lawyers on the floor?

JAN CRAWFORD GREENBURG: He jumped right in, now this is a very active court. All of these justices ask questions. They jump in, they cut each other off; they cut the lawyers off. And Chief Justice Roberts asked four or five questions of the first lawyer arguing the case, pressing him for his views on how he was interpreting this federal law. It was an employment law case. So he was very active.

Now Chief Justice Rehnquist also was somewhat active at argument, and would jump in and ask questions of his own. So we're not really sure and we didn't -- I didn't have a sense today of how different in terms of asking questions that the Chief Justice Roberts would be as opposed to Chief Justice Rehnquist. But his style might have seemed a little, I don't want to say -- not as stern as his predecessor, but he was very much in control.

RAY SUAREZ: And when you look at the cases in the pipeline, is this going to be a year with a lot of attention on the court?

JAN CRAWFORD GREENBURG: Oh, that's right, it a very controversial term. The court has a number of key issues, social issue cases, abortion, religion, free speech. So they are going to jump right in, they've got an assisted suicide case on Monday. So it will be quite a contentious term that they will be wrestling with these issues, with a new leader and then with a new nominee coming down the road, who perhaps could be confirmed by November.

RAY SUAREZ: Well, that assisted-suicide case you mentioned will be heard by Sandra Day O'Connor, who has agreed to stay on as an associate justice until her successor is sworn. What's the mechanics of that? She's going to hear some cases. And then leave.

JAN CRAWFORD GREENBURG: Right. It is a little odd. And some of the cases that she hears she won't actually, her vote won't count because if she is not on the bench when the decision is raised to the issues it won't count. So those decisions could come out and they could be either 5-3 or if they are 4-4, perhaps the court would hear re-argument and let the new justice -- if it's Justice Miers -- come in and hear arguments on that. Or they could just say it was 4-4 and the decision below will stand.

But Justice O'Connor today was very much the Justice O'Connor that we have seen over the years. She jumped in, she asked questions. She pressed the lawyers. So she was very active at argument and playing again a significant role from the bench. But what that role will be when the opinions come out, we'll just have to wait and see.

RAY SUAREZ: So there's no way technically for a future Justice Miers to play catch-up. If she wasn't sworn when a case was heard, she can't vote on it, right?

JAN CRAWFORD GREENBURG: Unless they want to reargue it for her. And there is precedent for that, and they don't have to do it the same way for every case. For example, when Justice Thomas came on the court, he missed the first couple weeks of argument. And in several of those cases the justices decided what they were deadlocked four to four, and they decided to have re-argument so that Justice Thomas could participate in them.

Now you would think that -- and this is an interesting point about how a new member can affect the dynamics of the court -- you would think in that case Justice Thomas would have the deciding vote, right, because it was 4-4, and he is coming on. He gets to hear argument. But in most of those cases he ended up being in dissent because some of the other Justices changed their minds when they reargued the case.

So a new justice coming on doesn't just necessarily mean one new vote. It can often change alliances and change the way the court looks at things. So the fact we have a new chief justice, the fact that we have another justice soon to be on the bench could mean historic change for this Supreme Court, a court that is divided 5-4 on a host of controversial social issues, as we said, many of which they will take up this term.

RAY SUAREZ: Jan Crawford Greenburg of the Chicago Tribune, thanks for joining us.

JAN CRAWFORD GREENBURG: You're welcome.