WASHINGTON — Judge Merrick Garland may well be the most moderate Supreme Court nominee anyone could expect from a Democratic president, but he's also a justice who could create the first liberal majority at the high court in more than 40 years.

That explains why President Barack Obama, Senate Democrats and liberal activists are convinced Garland, a superbly qualified judge with a cautious, centrist record, deserves a hearing and a confirmation vote. And it's why Republicans and conservative activists are just as fiercely determined to not grant that hearing.

One vote can make an enormous difference on a court that frequently splits 5-4. If Justice Antonin Scalia, a staunch conservative, is replaced by a moderate-to-liberal Justice Garland, the court would tip to the left on several key issues.

Legal analysts are now dissecting Garland's past opinions as a federal judge since 1997 on the U.S. Court of Appeals for the D.C. Circuit.

Garland's moderate views, preference for narrowly crafted rulings and tendency to defer to regulatory agencies and the executive branch — under both the Bush and Obama administrations — point to a reluctance to engage in the kind of judicial activism that has been condemned, at different times, by both liberals and conservatives.

In 2003, for example, Garland joined a majority 3-0 opinion at the D.C. circuit that sided with the Bush administration in blocking Guantanamo Bay detainees from using civil courts to challenge their detention. That ruling was later overturned by the Supreme Court. He also deferred to the Obama administration by often siding with the Environmental Protection Agency when its rules were challenged.

“He's worked in the government, and he tends to think the people there are doing their best and working in good faith,” said Georgetown Law Professor Irving Gornstein.

“Judicial restraint” was once the watchword of conservatives, particularly when Republicans held the White House and they didn't want interference from the courts. Today, with a Democratic president, it is liberals calling for federal judges to uphold the administration's actions. Conservatives, meanwhile, prefer judges who will restrict the powers of the executive branch, at least as long as Obama is in office.

The court's conservatives have increasingly pressed to restrain federal agencies and their regulations, including on issues like the environment and immigration. But Garland's appointment could stop that.

“(Garland) is almost always deferential to agency interpretations of statutes,” UCLA Law Professor Ann Carlson wrote Monday, adding that his record “at least suggests he is likely to uphold the president's signature climate initiative, the Clean Power Plan.”

The pending battle over immigration is another major test of regulatory power. At issue is whether Obama has the authority to temporarily suspend deportation and to offer work permits to several million otherwise law-abiding immigrants living illegally in this country.

The case will be argued in April before the eight justices. But the ninth justice will be in a position to decide what power the next president has when it comes to immigration.

On guns rights, Scalia was the foremost champion of the constitutional right to “bear arms.” His most important opinion, in District of Columbia v. Heller, declared, for the first time, that the Second Amendment protected an individual's right to have a gun at home for self-defense. It struck down an unusually strict D.C. gun-control ordinance. Prior to that time, the court's rulings had found that the amendment's protections related to a “well-regulated militia.”

Garland played a small role in that case. He voted in 2007 to have the full D.C. appeals court reconsider the issue after one of its panels, by a 2-1 vote, struck down the D.C. ordinance law as a violation of the Second Amendment, marking the first time a federal appeals court had declared an individual right to bear arms under the Second Amendment.

One area where Garland may lean to the right is on terrorism and national security. He worked as prosecutor at the time of the Oklahoma City bombing and the arrest of Ted Kaczynski, the so-called “Unabomber” who had repeatedly sent homemade bombs through the mail.

Just as Garland respects the work of environmental regulators, friends say he also respected the teams of FBI agents who pursued the Unabomber and other domestic terrorists.

dsavage@tribune.com