The start of the new Supreme Court term is upon us, and it has the potential to be another blockbuster. The court is considering a line-up of issues that could be the subject of any 2016 presidential debate: Cases involving affirmative action, consumer rights, and the labor movement are already on the docket, and cases involving abortion and immigration could be there soon.

As court watchers start handicapping these cases, many of the justices’ votes may seem predictable. And often they will be. But in some of these cases, one justice’s votes may be less predictable than many court watchers once thought: Chief Justice John Roberts.

Make no mistake about it, Roberts is a conservative. When it comes to some areas of the law and some legal questions, the chief justice has firm ideological convictions, and in those areas – race and access to the courts, to name just two – he has consistently voted to move the law dramatically to the right.

Those ideological convictions explain many of his votes during the court’s most recent term, on topics ranging from marriage equality to racial discrimination. And it will likely explain some of his votes this coming term. 

Consider the affirmative action case, for example. Given Roberts’s long record in race cases and his avowed belief that “[t]he way to stop discrimination on the basis of race is to stop discriminating on the basis of race,” it is not difficult to predict what the chief justice will do in this case. 

It could also explain his votes in this term’s consumer rights cases – Campbell-Ewald Company v. Gomez and Spokeo, Inc. v. Robins – in which corporations are seeking to limit individuals’ access to the courts. Once again, given Roberts’ consistent votes to side with corporate interests over individual ones and to close the courthouse doors, it’s not difficult to predict what he’ll do in those cases.

But those strong ideological convictions can’t explain all of his votes over the past ten years. There were a number of cases last year in which Roberts broke rank with at least some of his conservative colleagues, and the explanation for those decisions may have a lot to do with Roberts’ deep concern about the court as an institution and its legitimacy. Early in his tenure, he talked about the importance of keeping a “partisan divide out of the judiciary.”  He echoed those comments much more recently, talking about how he doesn’t want the court to be seen as just an “extension of the political process.” 

Those institutional concerns mean that in some cases, Roberts will vote where the law takes him, regardless of his own ideological views. As Roberts wrote in deciding the first health care reform case, his decision had nothing to do with his “opinion on the wisdom of the Affordable Care Act.” He echoed the same sentiment in last term’s ACA case, expressing his view that it is Congress’ responsibility to make the law. The court must “respect the role of the [Congress],” he wrote, and not “undo what [Congress] has done.” 

Those institutional concerns might influence his vote should a major challenge to President Obama’s executive action on immigration make its way to the Supreme Court. As in the health care cases, Roberts may be unwilling to see the high court turned into a tool in the ongoing political fight about immigration, especially given the strength of the administration’s arguments in favor of the executive action. 

Indeed, as there is increasing evidence that the political polarization in Washington may be tainting the court, Roberts has begun to distance himself from at least some of the other conservatives on the bench, at least some of the time. In fact, looking back over his first decade on the court, it’s clear there has been some shift in Roberts’ voting over time. Since his decision in the first health care case, there have been at least ten significant, divided cases in which Roberts parted ways with at least some of his conservative colleagues to vote with the court’s more progressive members. This shift may to some degree reflect the cases the court is taking up, but it also sends an important message that the chief justice desperately wants sent: just because a group of justices were all appointed by a president of the same party does not mean they will always vote the same way.

So as we mark the end of Roberts’ first decade and look ahead to the start of his second, one thing seems clear: there will always remain some cases in which it will be easy to predict the chief justice’s vote, but there will also be some in which no one should count him out. That combination of rulings is unlikely to win Roberts many friends with partisans on either side of the aisle. But that’s probably fine with this chief justice. And it’s certainly good for the Supreme Court.