WASHINGTON » President Barack Obama is trying to change the face of a federal judiciary that has a long tradition of white men passing judgment on parties from all walks of life — if he can get his nominees past the Senate.

Republicans have used the powers accorded the Senate minority party to slow Obama’s influence on the federal bench. But recent changes to Senate rules suggest the process may begin to move faster, at least at the lower, U.S. District Court level.

Under a recent bipartisan agreement, the Senate will limit debate on district court judge nominees to two hours, far below the 30 hours that used to be allowed. The hope is that it will curtail a tradition dating to the Clinton administration of the president’s opposing party stalling judicial nominees.

Democrats also used the tactic on some of President George W. Bush’s nominees, but the delays have been particularly long under Obama.

Nearly half of Obama’s nominees have waited for more than 100 days for confirmation votes, while less than 10 percent of Bush’s waited that long, according to White House figures. Most of the Bush nominees were approved in less than a month after clearing the Senate Judiciary Committee, the White House said.

Michael L. Shenkman, a fellow at the Center for Law and Politics at Columbia Law School who worked on Obama’s judicial nominations team in the first two years of his presidency, calculated that district judge vacancies across the country represented more than 275 lost years of judicial work and $160 million in wasted public resources during Obama’s first term.

"Having an empty bench means people don’t get their cases heard," Shenkman said, adding that federal law requires judges to give priority to criminal cases, so civil cases can face repeated delays. "It makes litigation more frustrating and more expensive."

Nationwide, 90 out of 874 federal judgeships are vacant, with 31 of those vacancies labeled emergencies by the judiciary because of heavy caseloads. The Senate Judiciary Committee approved 13 of Obama’s nominees Thursday.

White House press secretary Jay Carney argues that the judges approved by the committee are "extremely well-qualified" and "reflect the president’s unprecedented commitment to a judiciary that reflects the nation it serves." The group of 13 includes eight women, six minorities and one openly gay candidate.

"This needless delay is unacceptable, and these nominees deserve immediate consideration by the full Senate," Carney said.

White House officials express little hope that the Senate will change its ways.

They point to Wednesday’s confirmation of William Kayatta of Maine to the 1st U.S. Circuit Court of Appeals in Boston. Kayatta’s nomination a year ago was supported by both of Maine’s Republican senators. But other Republicans in the Senate refused to agree to a vote because of election-year politics, so Obama had to renominate Kayatta again this year, even though he ultimately won confirmation without much controversy and with 88 votes in support.

Caroline Fredrickson, president of the American Constitution Society for Law and Policy, says the change in Senate rules still won’t impact nominees to the federal circuit, where appeals are heard and judges have more influence. "Where I’m worried is that on the circuit court nominees, there will be a lot of delay and obstruction that’s completely unrelated to anyone’s merits," she said.

Despite the delays, Obama was able to make some progress on diversity in his first term, with more black, Hispanic and openly gay federal judges confirmed than in two terms under Bush, according to the White House. Nearly half of Obama’s confirmed judges have been women, compared with about a quarter for Bush and Clinton, the White House said.

Obama hopes to build on that diversity in his second term. Only seven of 36 nominations the president currently has pending are of straight white men. Compare that to the makeup of the roughly 780 judges currently active on the federal bench, where 425 are white men, according to the Federal Judicial Center. There are small percentages of minorities — 96 black judges, 70 Hispanic and 17 Asian.

In the 8th U.S. Circuit Court of Appeals based in St. Louis, a group called the Infinity Project was formed to promote more gender equality, with just one woman ever having been appointed to serve on the circuit. Executive Director Debra Fitzpatrick argues that a diverse bench enhances a court’s legitimacy by reflecting the population on which it passes judgment.

"You can’t always predict when and how and in what ways a person’s personal experience will illuminate a case," Fitzpatrick said. She pointed to the case of an Arkansas prisoner named Shawanna Nelson convicted of check and credit card fraud who filed a lawsuit over being shackled to a hospital bed while in labor.

Nelson’s attorney, Cathleen Compton, grew frustrated as she argued before the panel why her client, a nonviolent offender, didn’t pose a flight risk that required shackling. "I’m a little disadvantaged here, or maybe it’s you that are disadvantaged, because I’ve given birth and you haven’t. I can tell you that a woman about to deliver a nearly 10-pound baby is not going anywhere," she said.

The appeals court sided with Nelson, in an opinion written by the sole woman among the 11 judges that heard the case, Clinton-appointed Judge Diana Murphy.

Two weeks ago, Obama nominated another woman, Iowa public defender Jane Kelly, to the 8th Circuit.