WASHINGTON (Reuters) - President-elect Barack Obama will have a chance to appoint dozens of sympathetic judges to U.S. federal courts over the next four years, reversing the judiciary's shift to the right under President George W. Bush.
Aided by a Democrat-controlled Senate, the former constitutional law professor will appoint judges who could rule on issues raised by Bush's prosecution of wars in Iraq and Afghanistan, as well as divisive social issues like gay marriage, the death penalty and abortion.
Obama's appointments to the Supreme Court and the lower federal courts also will be in a position to hear challenges to policies he intends to pursue, such as an expanded government role in health care.
Judges can amount to a president's most lasting legacy because they enjoy lifetime appointments. Bush's Supreme Court appointees John Roberts and Samuel Alito are in their 50s and expected to be conservative voices on the high court for decades to come.
Obama, who opposed both nominees on the grounds that they were more likely to side with the powerful than the powerless, has said he views the law as a way to even out imbalances in society.
"We need somebody who's got the heart, the empathy, to recognize what it's like to be a young teenage mom," he told Planned Parenthood last year.
Liberals are optimistic.
"He has an opportunity and a window to select judges who can restore balance on these circuits and extend protections to workers, women and people of color, constitutional protections, that the Bush judges have refused to do," said Nan Aron, president of the liberal Alliance for Justice.
Obama's initial appointments are not expected to alter the ideological makeup of the Supreme Court because those seen most likely to retire are members of the court's liberal wing -- John Paul Stevens, Ruth Bader Ginsburg and David Souter.
But those appointments will be a setback for conservatives who have worked for decades to establish a majority of "strict constructionists" who interpret the Constitution literally.
"The net loss is you get younger people on (the court) who will perpetuate a view of the Constitution which conservatives would like to think is transient," said Manuel Miranda, chairman of the Third Branch Conference.
Court watchers say Obama will be under pressure to nominate a woman. Likely candidates include appeals court judges Diane Wood and Sonia Sotomayor, and Harvard Law School Dean Elena Kagan.
A second term in office would give Obama a greater opportunity to shift the court leftward. Curt Levey of the conservative Committee for Justice estimates that Obama would have a 75 percent chance of establishing a liberal majority if he serves through 2016.
Obama is likely to have a far greater impact on the lower courts, which handle the vast majority of federal cases.
Assuming normal retirement patterns hold, 58 percent of all appeals court judges would be Democratic appointees at the end of Obama's first term, up from 36 percent now, according to Russell Wheeler of the Brookings Institution.
All the nominees must be approved by the Senate. But thanks to a solid Democratic majority, Obama will likely encounter less resistance than Bush and former President Bill Clinton. Both faced chambers controlled by the opposing party.
Vice President-elect Joe Biden's long tenure on the Senate Judiciary Committee will also help, experts said.
"I don't have a sense that there's going to be an awful lot of confrontation. He's got a pretty strong hand in the Senate," Wheeler said.
Editing by David Alexander and Xavier Briand