Merrick Garland has the opportunity to become not only the newest member of the Supreme Court but also its most influential, taking a spot at the court’s center now reserved for Justice Anthony M. Kennedy.

If the 63-year-old Garland is confirmed by the Senate — and there is no bigger if in all of Washington politics — he would help fulfill President Obama’s goal of remaking the court and become a part of a five-member liberal majority chosen by Obama and President Bill Clinton.

Garland’s replacement of conservative icon Antonin Scalia would be the most significant shift on the Supreme Court since Clarence Thomas was confirmed in 1991 to replace the liberal civil rights giant Thurgood Marshall.

But more than that, Garland could occupy the pivotal role as the court considers the most controversial cases­ of the day: affirmative action, abortion, gun rights, campaign finance regulation, the death penalty.

For a decade, a version of that role has been played by Kennedy, the most powerful of the nine justices and the one who most often casts the deciding vote when the court’s conservatives and liberals deadlock.

In a surprise move, President Obama has selected appeals court judge Merrick Garland to replace Justice Antonin Scalia. The Post's Jerry Markon explains the possible strategy behind his choice. (Claritza Jimenez,Gillian Brockell/The Washington Post)

Just as Kennedy is to the left of the rest of the court’s Republican-nominated conservatives — and thus the justice most often in play — most scholars of the court think that Garland would probably be just to the right of all of the court’s liberals.

No one knows for sure. But a review of his record on the U.S. Court of Appeals for the D.C. Circuit and interviews with those who have watched him for years as a prominently mentioned Supreme Court hopeful see someone whose instinct is for the middle.

“If confirmed, he’ll surely become the swing vote in most of the highly politicized cases, but more because he is a centrist than because he vacillates between more progressive and more conservative ideals,” said Stephen I. Vladeck, a professor at American University’s Washington College of Law who watches closely the work of the D.C. Circuit, of which Garland is chief judge.

Like others, Vladeck is most struck by the lack of controversy in a judge who has been on the bench nearly 20 years.

“Chief Judge Garland’s jurisprudence is the epitome of centrist, case-by-case adjudication — not because he lacks deep methodological commitments, but because he’s never been prone to go out of his way to wax philosophical about those commitments,” he said. “He has a remarkable dearth of separate opinions, and even his majority opinions tend to be fairly efficient, technical resolutions of the legal questions before him.”

Moreover, Garland is well known to the Supreme Court. More than 40 of his clerks have gone on to clerk for the justices, about a quarter of them for conservative members of the court. Such cross-pollination is increasingly rare.

“Many fine Supreme Court justices took time to get their bearings,” said Justin Driver, a University of Chicago law professor who clerked for Garland and Justices Sandra Day O’Connor and Stephen G. Breyer.

President Obama is nominating Merrick Garland to replace Justice Antonin Scalia on the Supreme Court. He introduces himself in this White House video. (White House)

“That would not be him,” Driver said. “He would hit the ground running.”

Garland is known as a technical craftsman, with careful opinions that follow rather than push back at precedents either at his own court or the Supreme Court. He ranked in the top 10 percent of judges appointed in 1997 or after in a measure of both the quantity and quality of their work, according to an analysis by Ravel Law, a legal research and analytics start-up.

Despite nearly two decades on what is often called the second-most-important court in the country — its judges often are nominated to take the next step to the high court — he has relatively few controversial rulings.

The court often hears important government and regulatory cases but is rarely called upon to decide dramatic social issues such as affirmative action, abortion, same-sex marriage or the death penalty. Those have become staples at the Supreme Court.

Conservatives acknowledge they have come up with a limited list of complaints. Edward Whelan, president of the Ethics and Public Policy Center, a conservative think tank that is normally a scourge of liberal jurists, acknowledged in a conference call with reporters that “the only criticism I’d make of him is that he’s a liberal.”

Carrie Severino of the conservative Judicial Crisis Network criticized Garland as anti-Second Amendment. In 2007, he voted with the losing side on whether the entire D.C. Circuit should review a panel’s decision that struck down the District’s restrictive gun-ownership laws.

She and Brian Rogers, executive director of the Republican group America Rising Squared, said Garland may be the “most anti-gun nominee” in decades.

But a Republican judge joined Garland in saying that the landmark ruling about the Second Amendment’s protection of individual rights should be reviewed. The whole court did not take up the merits of the panel’s decision. The Supreme Court agreed with the appeals court in a dramatic 5-to-4 decision, with the majority opinion written by Scalia.

But it would probably be just as accurate to describe Garland as the most conservative Supreme Court nominee by a Democratic president in decades. His prosecutor background and some of his rulings on the D.C. Circuit indicate that he would not take uniformly liberal positions on criminal justice issues; on the circuit, he is more likely to side with the government than his liberal colleagues.

He is also deferential to government agencies, such as the Environmental Protection Agency, and his rulings on labor issues are supported by unions. Liberal groups that might have wanted a more outspoken champion nonetheless say privately that they are confident that Garland would move the court in their direction.

That was Whelan’s point, too: When it comes to the Supreme Court, a “supposed moderate liberal” is as good as any other kind of liberal.

Garland has always been seen as the “safe” nomination that Obama kept in his back pocket. The president acknowledged that he considered Garland twice before and, with a Democratic-controlled Senate, opted instead for Sonia Sotomayor and then Elena Kagan.

Garland looks more like a left-leaning version of Chief Justice John G. Roberts Jr.: a Midwesterner with double degrees at Harvard who clerked for the same circuit judge, moved on to work for Supreme Court justices, served on the D.C. Circuit and made friends on both sides of the aisle.

No one seriously doubts that Garland would move the court to the left and that his presence holds the promise for a reversal of the court’s trends on issues such as voting rights, environmental issues and, perhaps, campaign finance regulation.

That is why the fight over his nomination is likely to be so fierce.