WASHINGTON - APRIL 16: University of California at Berkley Law Professor Goodwin Liu testifys before the Senate Judiciary Committee during his confirmation hearing to be U.S. Circuit Judge for the Ninth Circuit April 16, 2010 in Washington, DC. Liu, who has been very critical of conservative judges and nominees, may be the toughest fight over any of President Barack Obama's appeals court nominees because of Liu's liberal views. (Photo by Chip Somodevilla/Getty Images)

WASHINGTON -- There are two ways the Obama administration could end the corporate world's current winning streak when it comes to U.S. Supreme Court decisions: A justice could die, or one could retire.

Since the conservatives on the court almost certainly would wait until a Republican president is in office to consider retirement, the only option -- other than waiting for someone to die -- is to put progressive lawyers on the federal bench and in federal appeals courts. Since the Supreme Court takes only a small portion of cases, those appointees could potentially have more impact on combating the pro-corporate influence of the federal judicial system.

Until recently, the Senate filibuster was a major obstacle to pushing progressives through the judicial nomination process. But with or without the congressional stalemate, progressives haven't been thrilled with President Barack Obama's choices for the last five years.

"A lot of people in the progressive community have been disappointed with the president's nominees," said Adam Winkler, a professor at UCLA. "They feel there aren't many people from the major public interest organizations, or activist lawyers groups who might really understand income inequality."

"Even though you're getting Democratic appointees, and you're probably getting people who are left-of-center, or center, there's a sense that the judges you're getting are very moderate and not likely to challenge the pro-corporate bias of American law," he continued.

Democratic presidents used to select nominees with a background in civil rights, or those who worked for legal organizations known for their progressive stances. Justice Ruth Bader Ginsburg, an early Clinton nominee, used to work for the American Civil Liberties Union. But now, such an affiliation can be seen as a disqualifier.

"I think it would be very difficult to get somebody confirmed from a major civil rights organization today," said Winkler. "One of the big measures of judicial activism for Republicans is membership in a civil rights organization."

Working for a place like the ACLU is essentially "placing a neon sign above their head saying, 'I'm a big lefty,' and the Republicans know exactly who to block if that person is nominated," said Ian Millhiser, a senior constitutional policy analyst at the Center for American Progress Action Fund.

Academics can be more difficult, since they tend to produce a lot of written work that can serve as great opposition material for Republicans seeking to prevent their confirmation. In the current structure of the legal profession, top graduates typically go to law firms representing corporate clients. So the judicial nominees Obama has turned to recently tend to come from within the federal government or corporate firms.

The administration may still feel rattled by its inability in 2011 to push through Goodwin Liu, a liberal professor who was nominated to the 9th U.S. Circuit Court of Appeals (and now sits on the California Supreme Court).

"I think the White House has been preoccupied with just making sure their nominees can be confirmed. I think they felt bitten by the experience of Goodwin Liu and they didn't want to do that again," said Millhiser. "When you take the neighborhood of plausible Democratic judicial nominees and you skim off the top the people that Republicans might object to, what you're left with is a pool that's going to have many more people who are going to have pro-corporate attitudes than the Democratic pool as a whole."

But some think the administration took the wrong lesson from its struggles with Liu.

"The problem with the administration is that it should be appointing 10 Goodwin Lius, and two or three of them wouldn't get through, but some of them will," said Winkler. "That's what Republican presidents did very well, is they nominated a lot of true believers and some would get dinged for being too extreme, but some would get through. I think Democrats are disappointed because they don't believe they're getting true believers appointed to the court."

Even though the filibuster for nominees became history in December, it could take a while before the administration names more progressive nominees to the federal bench, since the vetting process takes so long. "The filibuster change happened, and I don't know how fast -- even if the White House is determined to go out and nominate the best lawyer at the ACLU -- how fast they'd be able to churn through the vetting process to make that happen," said Millhiser.