Speaking at the University of Chicago Law School, where he taught for 10 years, Obama argued that without substantive concerns about Garland's record, Republicans were blocking his nomination solely on political grounds.
And he pushed back on criticism Garland wouldn't bring diversity to the court, claiming his past judicial nominations "transformed the courts from a diversity standpoint" and that he didn't set out to find a candidate from a particular demographic.
"At no point did I say, 'Oh, I need a black lesbian from Skokie," Obama said, referencing the small Chicago suburb where Garland was raised. "Yeah he's a white guy, but he's a really outstanding jurist. Sorry, I think that's important."
"Merrick Garland is an extraordinary jurist who is indisputably qualified to serve on the highest court of the land. And nobody really argues otherwise," Obama said. "No one has plausibly made an argument that this is not the kind of person we'd want on the Supreme Court. The question then becomes: Why is it so hard for the guy just to get a hearing and a vote?"
Obama and his allies have launched an aggressive pressure campaign on Republicans to take up Garland's nomination, which Obama announced in a Rose Garden ceremony last month. They've argued Senate Majority Leader Mitch McConnell and the Republican chairman of the Judiciary Committee, Chuck Grassley, are shirking the Senate's constitutional obligation to consider the President's pick for the high court.
Obama on Thursday said the longer the high court goes without a full roster of justices, the higher the likelihood of the court becoming bitterly politicized.
"If you start getting into a situation in which the process of appointing judges is so broken, so partisan that an imminently qualified jurist cannot even get a hearing, then we are going to see the kinds of sharp partisan polarization that have come to characterize our electoral politics seeping entirely into the judicial system," Obama said.
Grassley attacked Obama following his event, in a fundraising letter where the Iowa senator portrayed Obama's Supreme Court campaign "a publicity stunt to get his way."
"There is so much at stake in 2016," Grassley wrote. "The opportunity to win back the White House, to secure the Republican Senate Majority and influence the direction of the Supreme Court for the next generation."
During a town hall-style event, Obama was questioned about the Democratic race to replace him, which he said hadn't reached nearly the level of rancor as the Republican side. But he warned his party against adopting an overly strict doctrine that excludes differences in opinion.
"The thing that Democrats have to guard against is something the Republicans are going much further along on, and that is this sense that we are just going to get our way, and if we don't we're going to cannibalize our own," he said.
And while he didn't delve deeply into the political race Thursday, Obama is expected to use the Supreme Court issue as a cudgel in the coming election.
While a growing number of Republican senators have agreed to meet Garland in their offices on Capitol Hill, that effort hasn't yet produced a crack in McConnell or Grassley's refusal to convene committee hearings on Garland's nomination.
The first Republican to meet with Garland, Sen. Mark Kirk of Illinois, didn't attend Obama's event in his home state Thursday, but did receive a handwritten thank you note from the President for his "fair and responsible treatment" of the nominee.
"It upholds the institutional values of the Senate, and helps preserve the bipartisan ideals of an independent judiciary," Obama wrote in the note, which Kirk posted on social media Thursday.
A day earlier, Obama and Vice President Joe Biden endorsed Kirk's Democratic challenger for the Senate, Rep. Tammy Duckworth, signaling the President would actively campaign against the Republican incumbent as November's election nears.
Asked about the decision to endorse Duckworth a day before visiting Chicago, White House spokesman Eric Schultz told reporters Obama made his decision based solely on the two-term congresswoman's qualifications. But Democratic officials have said that they plan to use the Supreme Court issue against Republicans senators up for re-election, like Kirk, Kelly Ayotte of New Hampshire, Rob Portman of Ohio and Pat Toomey of Pennsylvania.
Obama -- with an eye toward polls showing that even a majority of Republicans support hearings -- hopes to drive a wedge between the Senate leaders and members of their party when he appears on Fox News this weekend. He planned to tape an interview with the network's Sunday morning program after his session in Chicago. White House Press Secretary Josh Earnest said he hoped to reach an audience that "may not have heard from the President directly in a while."
The trip to the Windy City amounted to a homecoming for Obama, as well as his daughter Malia, who accompanied her father on Air Force One en route to his speech. Obama spent a decade on the faculty of the University of Chicago law school, joining as a professor in 1992, teaching three courses a year until he was elected to the U.S. Senate in 2004. The school said Obama was invited several times to join the faculty in a full-time tenure-track capacity but declined.
The home Obama and his family still maintain in leafy Hyde Park was less than two miles from where Obama spoke Thursday.