Editor’s Note: Jeffrey Toobin is chief legal analyst for CNN and the author of “The Nine” and “The Oath.” The opinions expressed in this commentary are his own. View more opinion at CNN.

CNN  — 

In the waning days of Donald Trump’s presidency, Amy Coney Barrett won confirmation to the Supreme Court and Clarence Thomas received an equally consequential promotion – to Chief Justice of the United States.

Not officially, of course. John G. Roberts, Jr., retains the title and the middle seat on the Supreme Court bench. But the Chief Justice has just one essential power that differentiates his role from that of the other Justices. The Chief has the right to assign the court’s opinions when he is in the majority. When the Chief Justice is in the minority, though, the assignment power goes to the senior Associate Justice who is in the majority.

Thomas, who was confirmed in 1991, is now the longest tenured Justice on the court. More notably, he is now the leading figure among the five solid conservatives on the court – Thomas himself, Samuel Alito, Neil Gorsuch, Brett Kavanaugh, and Barrett.

In crucial, contested cases, Chief Justice Roberts has increasingly been voting with the three remaining liberals – Stephen Breyer, Sonia Sotomayor and Elena Kagan. If Roberts continues this pattern, that means Thomas will be the senior Justice in several significant 5 to 4 cases and thus enjoy the right to assign majority opinions, including, of course, to himself.

Thomas has long occupied a peculiar niche on the court. He has been a part of the conservative majority in a mostly conservative era, but he has written few important majority opinions himself. Roberts gave himself blockbusters like Shelby County v. Holder, the 2013 case that eviscerated the Voting Rights Act, and when liberals cobbled together winning coalitions, they usually gave the big assignments to Anthony Kennedy, as in the 2015 case Obergefell v. Hodges, which guaranteed the right to same-sex marriage.

There’s little doubt why Roberts and, before him, Chief Justice William H. Rehnquist declined to give Thomas important assignments. Even among conservatives during Thomas’s earlier years on the court, his views were seen as extreme and eccentric. Like the late Antonin Scalia, Thomas is an originalist, which means he believes the Constitution should be interpreted as its words were understood to mean when it was ratified, in the 18th century. But Thomas and Scalia differed in their approach to stare decisis – the law of precedent. Scalia joined with virtually all Justices who have served on the court in believing that the Justices should usually respect the court’s precedents, even if he himself would not have joined the majority in the original case.

The idea behind this approach is that it’s important for the law to project stability and allow citizens to order their lives according to predictable rules. Thomas disagrees. He thinks precedents that conflict with his understanding of the Constitution should be overturned – immediately and en masse. As Thomas put it in a concurring opinion in 2019, “When faced with a demonstrably erroneous precedent, my rule is simple: We should not follow it.” In an appearance at a New York synagogue, I once heard Scalia give a memorable quip when he was asked about the difference between his approach and Thomas’s. “I’m an originalist,” Scalia said, “but I’m not a nut.”

Even more that his fellow conservatives, Thomas believes in prohibiting virtually all forms of gun regulation under the Second Amendment ; restricting press freedoms; allowing unlimited campaign contributions and spending under the First Amendment; banning all forms of affirmative action based on race and allowing virtually all forms of executions, no matter how painful.

In addition, of course, Thomas has long favored overturning Roe v. Wade, which he regards as “grievously wrong,” and allowing states to ban abortion. It appears that Roberts and Rehnquist knew that, in major cases, Thomas’ singular views and approach to precedent could not command a majority of even his conservative colleagues, so they assigned him relatively unimportant majority opinions – the dogs, in Supreme Court argot. But Thomas will not give himself the dogs. He will have the right to keep the big opinions to himself and the opportunity to hold on to the votes of the four other conservatives.

Thomas has already exercised his assigning power in a consequential case. On November 25 last year, the court ruled, 5 to 4, that New York Gov. Andrew Cuomo violated the First Amendment’s guarantee of free exercise of religion when he banned religious gatherings of more than 10 people in some areas, as a means of containing the Covid-19 pandemic. With Roberts in the minority, Thomas assigned the opinion, directing that it be published “per curiam,” or by the court, which the Justices usually reserve for routine or non-controversial matters.

The message of the assignment was that this was an easy case, one in keeping with the conservatives’ push on the Supreme Court to allow religious people to exempt themselves from rules that apply to others, like the obligation of employers to pay for health insurance, including birth control, for their employees. Over the course of the Supreme Court’s term that began last October, according to Adam Feldman of the Empirical Scotus blog, Thomas was the senior Justice in the majority at least five times.

Get our weekly newsletter

  • Sign up for CNN Opinion’s new newsletter.
  • Join us on Twitter and Facebook

    Next term promises to showcase Thomas’s leadership in even more consequential areas. In the fall, the court will hear a challenge to Mississippi’s new abortion law, which would ban almost all abortions after the 15th week of a woman’s pregnancy. Ever since Roe, in 1973, the court has held that states cannot ban abortions before a fetus is viable – well after 15 weeks – but legislators in Mississippi passed the law in hopes that the Supreme Court would use it as a vehicle to overturn Roe.

    In 2020, Roberts sided with the four liberals then on the court (including Ruth Bader Ginsburg) to overturn a restrictive abortion law from Louisiana. In his separate opinion, Roberts said the principle of stare decisis dictated his vote in the case. Thomas, joined by Justices Alito, Gorsuch, and Kavanagh, dissented.

    Next term, of course, the four dissenters in the Louisiana case will be joined on the court by Barrett, whose anti-abortion views may have been the key factor that led Trump to nominate her. In other words, there will likely be a majority of Justices opposed to abortion rights, even if Roberts dissents. In that case, Thomas will have the right to assign the opinion. And his views on Roe could not be clearer. “Our abortion precedents are grievously wrong and should be overruled,” Thomas wrote in his 2020 dissent. “The idea that the Framers of the Fourteenth Amendment understood the Due Process Clause to protect a right to abortion is farcical.” Thanks to the arrival of Barrett, on abortion and a host of other cases, Thomas may soon have the power to make such a view the law of the land.