Settling for a centrist candidate with nearly two decades of judicial experience, President Barack Obama on Wednesday nominated Merrick Garland, a federal appeals judge in Washington, D.C., to the Supreme Court seat left vacant by the death of Justice Antonin Scalia.

"I said I would take this process seriously, and I did," Obama said while announcing his choice from the Rose Garden at the White House, adding: "The one name that has come up repeatedly -- from Republicans and Democrats alike -- is Merrick Garland."

Garland was visibly emotional when Obama gave him the microphone.

"This is the greatest honor of my life, other than Lynn agreeing to marry me more than 20 years ago," Garland said, his voice breaking as he motioned to his wife in the audience. "For me there could be no higher service than serving as a member of the United States Supreme Court."

If confirmed, Garland, 63, wouldn't bring diversity to the court as much a lengthy résumé in public service, including stints in the Department of Justice and on the U.S. Court of Appeals for the D.C. Circuit, where he has served since 1997 and is now the chief judge.

An eventual appointment for Garland is also less likely to mark a liberal shift in the Supreme Court. If anything, his contributions -- given his age and his moderate record so far -- are likely to be more pragmatic than path-marking for some of the country's most hotly contested legal issues, such as voting rights, gun control and the scope of presidential powers.

For those very reasons, Garland is the least controversial -- and likely the most confirmable -- of all the candidates who were reportedly considered for the vacancy. It is possible Obama chose him for the post to defuse the confirmation fight that Senate Republicans have promised since the moment Scalia died.

In his remarks, Obama pointed to the coming gridlock while highlighting the consequences for the court.

"Our Supreme Court really is unique. It's supposed to be above politics. It has to be. And it should stay that way," he said. "To suggest that someone as qualified and respected as Merrick Garland doesn't even deserve a hearing ... would be unprecedented."

Obama seriously considered Garland in 2010 for the opening created by the retirement of Justice John Paul Stevens. He was ultimately passed over for Elena Kagan, then the president's top lawyer before the Supreme Court. He was also considered in 2009, when Justice Sonia Sotomayor replaced the retired David Souter.

Garland has some pluses that could serve him well in a polarized environment, including knowing Chief Justice John Roberts -- the two clerked for famed New York judge Henry Friendly and participated in cases together on the D.C. Circuit, when Roberts served there between 2003 and 2005.

An honors graduate of Harvard Law School, Garland is also chief judge of a federal court that's widely regarded as second only to the Supreme Court: The D.C. Circuit is not only a pipeline of sorts for future justices -- Scalia and Justices Clarence Thomas and Ruth Bader Ginsburg also sat there -- but it also hears major challenges to federal regulatory action, including cases on net neutrality, health care and the environment.

"Judge Garland's record demonstrates that he is essentially the model, neutral judge," wrote SCOTUSblog publisher Tom Goldstein in 2010, when the White House was vettting him for a seat on the high court. "He is acknowledged by all to be brilliant. His opinions avoid unnecessary, sweeping pronouncements."

But Supreme Court observers and advocacy groups were hoping Obama would choose to make history again and ensure a deeper legacy -- like when he nominated Sotomayor, the court's first Latina. To that end, many thought he'd go with the much younger but equally qualified Sri Srinivasan, a colleague of Garland's on the D.C. Circuit who could've been the nation's first Asian-American and Hindu justice.

On that point, the same SCOTUSblog -- which last month featured a blog post by the president outlining what he was looking for in his next nominee -- was more blunt.

Progressive groups will fall in line, and deeply respect Garland and the President’s choice, but their actual disappointment will be deep. — SCOTUSblog (@SCOTUSblog) March 16, 2016

Under the Constitution, it is now the Senate's role to consider Obama's nomination, providing the necessary "advice and consent" to decide whether Garland should be confirmed to the Supreme Court.

Since Scalia's death, Senate Judiciary Committee Chairman Chuck Grassley (R-Iowa) and Senate Majority Leader Mitch McConnell (R-Ky.) have repeatedly vowed to not even consider anyone the president nominates, arguing that whoever wins the general election in November should name the next justice.

This has enraged Democrats and sparked weeks of political mudslinging, charges of opportunism and accusations that Senate Republicans are refusing to do their jobs.

At a recent Senate Judiciary Committee meeting, Sen. Lindsey Graham (R-S.C.) candidly recognized that his party's obstructionism over the nomination was more about politics than anything else.

In response, the White House and progressive groups are ready for what looks to be a monumental fight to get the nominee confirmed -- setting their sights on Republican incumbents, including Grassley, whose staunch opposition to holding confirmation hearings could backfire at the polls.

The president's strategy includes an aggressive digital push, which, as of Wednesday, featured a short video documentary of Garland's life.

Meet Chief Judge Merrick Garland, the President's nominee to the Supreme Court. #SCOTUSnominee https://t.co/ACujysyyDJ — SCOTUS Nomination (@SCOTUSnom) March 16, 2016

Republicans are planning a ground game, too, forming their own "SCOTUS task force" to combat whatever the White House and its allies may have up their sleeves.

"This will be the most comprehensive judicial response effort in our party's history," Republican National Committee Chairman Reince Priebus promised in a statement.

Following Wednesday's announcement, there were some signs among Republicans in tough re-election battles -- among them Sens. Mark Kirk (Ill.), Kelly Ayotte (N.H.) and Rob Portman (Ohio) -- that they'd be willing to at least meet with Garland, who will be visiting Capitol Hill on Thursday.

Speaking about his legal background at a conference at the Georgetown University Law Center in 2013, Garland seemed to presage the confirmation fight that awaits him.

"They tell you in Washington, that if you want a friend, get a dog. Harry Truman said that," Garland said. "That is not true. Get a family. That is a hard place to be. No matter how much honor you have, people will attack you one way or the other. And the principal solace that you get is from your family because they're behind you no matter what happens."