Roberts joined the Supreme Court in 2005, seen as a staunch, across-the-board conservative. In recent years, though, he’s appeared to moderate some of his positions, in specific instances and sometimes in very nuanced ways. That kind of shift could have significant effects on how the current court decides major issues and — if it represents a permanent change — on how Roberts leads the court into the next decade.

Win Mcnamee / Getty Images Chief Justice John Roberts last year.

WASHINGTON — Thirteen years into the job, Chief Justice John G. Roberts Jr. remains a conservative — but he has shifted to a more moderate position among the conservative justices on the court, a small change with potentially dramatic consequences.

Among the justices appointed by Republican presidents, Roberts agreed least with Justice Anthony Kennedy in Roberts’ first two terms leading the court, and the most with Kennedy in the two most recently completed terms. That kind of shift could have significant effects on how the current court decides major issues and — if it represents a permanent change — on how Roberts leads the court into the next decade. President George W. Bush nominated Roberts to be the next chief justice of the United States in 2005 when William Rehnquist died. Roberts had been a clerk for Rehnquist and was a former Reagan administration Justice Department official who later worked in the White House counsel’s office, meaning conservatives had — and many still have — high expectations for Roberts to lead the court in a staunchly conservative direction. And that’s still true on many matters, from high-profile cases on abortion and affirmative action to those involving economics and business concerns. But a more complicated picture emerges when the past few years are closely examined, even on some of the more divisive issues before the court. Roberts has found himself moving ever so slightly away from the doctrinaire conservative position he held when he started on the high court — having shown repeated interest in taking actions that are aimed at protecting the institutional integrity of the court and governmental stability more broadly, in the court’s approach to the Affordable Care Act and by its handling of the marriage equality cases. It is not necessarily an ideological shift; it could be seen as a pragmatic, or even protective, move. It also is not yet clear if this movement from Roberts is a long-term change or a temporary shift in response to the current ideological split on the court — or even the dynamics of the Trump candidacy and presidency. After all, Roberts’s very being is — within the conservative world — a type of anti-Trump. While President Trump came into office on a promise of “draining the swamp,” Roberts was a federal appellate judge in DC before his nomination to the high court and he had served in the two prior Republican administrations before that. Trump is a constant presence on TV and Twitter; Roberts is not (and runs a court that has no video of its proceedings and delays the release of audio so it can’t appear in news coverage of the day’s arguments). And, perhaps most importantly, as Trump takes aim at institutions across Washington, Roberts, in his dozen years on the Supreme Court, has shown an affinity for taking actions to protect governmental institutions — an affinity that has only grown in recent years. Now, with the addition of Justice Neil Gorsuch to the high court, the reformulated nine-person bench is deep in its hearings for Roberts’ 13th term leading the Supreme Court, and it is unclear how the court will resolve key questions about balancing religious liberty and nondiscrimination laws, the consideration of political and racial gerrymandering claims, the application of the Fourth Amendment in the “cloud” age, and more. More than three months into the new term, the justices have issued only one opinion from an argued case — a unanimous decision in which Justice Ruth Bader Ginsburg wrote the opinion. Adam Feldman at Empirical SCOTUS noted in December that you’d have to go back to 1869 to find a term when the court didn’t issue its second opinion until January. While the court obviously has given no reason for the dearth of opinions, it does mean that opinions haven’t been ready. And if opinions aren’t ready, that means that there are difficulties either resolving a few key cases or resolving many cases. Difficulties could range from something as significant as a situation where the court is split three (or more!) ways on how to resolve a case and unable to reach a majority opinion, to something as minor as continued disputes between the authors of drafts of the court’s majority opinion and justices’ dissenting opinions. These opinions, once the court starts issuing them as early as Monday, could tell us much more about the direction of the court — and what is driving Chief Justice John Roberts, one of the most important people in America.

Charles Dharapak / ASSOCIATED PRESS

Statistics from Roberts’ first dozen terms on the high court show a growing willingness to be less doctrinaire in his conservatism — particularly in order to agree with Justice Anthony Kennedy.

For his first eight terms on the court, Roberts agreed most with Justice Samuel Alito (one of the staunchest conservatives on the court), according to statistics compiled by SCOTUSblog. For three of the past four terms, he agreed most with Kennedy. (The SCOTUSblog statistics lay out the percentages of times when the justices agreed with one another on three levels: (1) agree in part, all, or judgment; (2) agree in part or all; and (3) full agreement.) It’s not just that Roberts is agreeing more with Kennedy; he’s agreeing with some of the more liberal justices more and the more conservative justices less. In three of those recent terms, Roberts agreed with Justice Stephen Breyer, at least in judgment, in the same percentage of cases as he agreed with one of the more conservative justices (Alito twice and Justice Clarence Thomas once). In two terms, he agreed with Justice Elena Kagan more than he did with one of the more conservative justices (Alito in one instance and Thomas in another). (This is not necessarily all Roberts’ doing. Breyer is by no means an unbending liberal vote on the court, and Kagan has shown a similar tendency in her time on the court.) Roberts still disagrees with Kennedy and even more often with Breyer and Kagan — sometimes in key cases, often in ideologically divided cases — but the movement is there. Statistics give only part of the picture, though. In some of Roberts’ most prominent legal moves — and in some more quiet ways — on the Supreme Court itself, he has etched out a position of conservatism that sometimes values the interests and stability of the Supreme Court and federal government more broadly to a greater degree than political conservatives might wish to see. In 2012, Roberts famously — or infamously, in some corners — joined the more liberal members of the court in upholding the Affordable Care Act’s individual mandate, a move that kept the court from striking down one of the most significant pieces of legislation passed by Congress and signed by the president in recent decades. Three years later, joined by Kennedy this time, Roberts again protected Obamacare from court-imposed destruction — upholding the insurance subsidies implemented under the law nationwide. Those moves provoked outrage on the right that continued through to the 2016 Republican presidential primary. But those decisions also can also be read as Roberts trying to prevent governmental instability by deferring, ultimately, to the other branches of government. (Notably, Roberts similarly voted against overturning the decisions of the other branches of government in one of the prominent times when he disagreed with Kennedy in writing in recent years — the 2013 challenge to the Defense of Marriage Act.) In the marriage cases themselves, it likely was Roberts who helped avoid a constitutional scenario in which the court would have been seen as being “responsible” for expanding the rights of same-sex couples to marry in roughly 60% of the country. Instead, the ultimate June 2015 ruling changed the law on the ground in only about 25% of the country. Whether it was based on a hope that the court could avoid the matter altogether through unanimity at the lower courts or was just an effort to delay a ruling from the high court, the Supreme Court made a series of moves that suggests a strategy of minimizing the amount of disruption seen as coming from the high court. The court that decided to hear the case over California’s Proposition 8 marriage amendment in December 2012 also decided against taking up the appeals from several other states in October 2014. That decision, in turn, expanded the number of states with marriage equality dramatically by the time the Supreme Court later agreed to hear appeals from same-sex couples in other states in April 2015. Although Justices Antonin Scalia and Clarence Thomas made it clear that they believed the court should have heard the October 2014 cases, at least Roberts or Alito (or both of them) must have voted against doing so at that time. Although we can’t, at this date, be certain that Roberts cast a vote allowing that marriage equality expansion, there is much more reason to believe that Roberts — with his institutional concerns — would have voted to do so than Alito. Finally, when it comes to the death penalty, Roberts has shown a willingness to go along with Kennedy — or, at the least, not voice his opposition — on a handful of capital cases in which the court sided with death-row inmates. This does not mean he always votes against the death penalty. Instead, it means merely that he has shown a willingness to consider tossing out death sentences in certain cases in which Kennedy himself has clear concerns. In each of the past two terms, Roberts has authored a majority opinion siding with a death-row inmate. (Neither Thomas nor Alito joined either opinion.) In recent years, he also has agreed with (or at least not voiced his dissent to) per curiam decisions siding with death-row inmates — cases in which Thomas and Alito, and now Gorsuch, regularly voiced their dissent. Even where Roberts disagreed with Kennedy in the resolution of one of the court’s capital cases in recent years — over the way states determine who is intellectually disabled and thus exempt from the death penalty — Roberts agreed with Kennedy (and the court majority) that the test at issue used by Texas was improper. (There was one instance in which Roberts joined the more liberal justices to halt an execution where Kennedy did not do so, but that was a stay of execution in which Roberts made clear he was only doing so as a “courtesy” to the four justices who wanted to consider whether to grant certiorari in an inmate’s case. They ultimately did not, and the man has since been executed.) Even the court’s approach to Trump’s travel bans has shown a desire to avoid the most contentious outcomes for the court — and the public — through its orders. This was most notably achieved in the order from June 2017 that allowed the partial implementation of the second ban while allowing those with ties to the US to be exempted from it — an order that allowed each side to claim some semblance of victory and pushed off any merits consideration that could be less malleable to compromise. Notably, Thomas, Alito, and Gorsuch wrote to say they would have allowed the full ban to go into effect — a statement that neither Roberts nor Kennedy joined.

Win Mcnamee / Getty Images Roberts (right) walks out of the Supreme Court with Neil Gorsurch last year.