David SouterJustice David Souter, a New Hampshire Republican who became a key liberal vote on the Supreme Court, plans to retire this summer, according to media reports late Thursday. The retirement will clear the way for President Barack Obama to make his first nominee to the high court.

Since the court has only one woman among its nine justices, most observers have predicted that Obama would select a woman as his first choice. There is no obvious successor to Souter, however, and the new administration has had only three months to sift through the potential nominees.

Souter’s departure comes as no surprise to his colleagues and others who know him well. He has been in a good health, and at age 69, he is not old by the standards of the high court. But he intensely dislikes Washington, has few friends in the capital and leads a solitary life. He has often said his mood brightens when he can return home to New Hampshire.

Even though two of his favorite colleagues _ 89-year-old John Paul Stevens and 76-year-old Ruth Bader Ginsburg_were often the center of retirement speculation, talk around the court this year has focused on Souter’s likely departure. He had not hired law clerks for the fall, also leading many to foresee he planned to step down when the court’s term ends in June.

His retirement is not likely to change the court’s ideological balance. He has been a reliable liberal on all the major issues decided recently, including abortion, civil rights, religion, Guantanamo and the death penalty.

He has also voiced frustration with the court’s conservative drift of late. On Wednesday, he sharply questioned a lawyer who wanted the court to strike down part of the historic Voting Rights Act of 1965. Souter said the nation has made progress on civil rights, but he added he did not see a “radical” change that would justify repealing much of the Voting Rights Act.

Souter’s pending retirement puts another important issue before Obama. He is a former professor of constitutional law at the University of Chicago and has a thorough knowledge of the issues before the court. He also knows well many lawyers and judges who could be nominated to the high court.

Obama chose Harvard Law Dean Elena Kagan to be the solicitor general, the administration’s lawyer before the court. But she has yet to argue a single case. Judge Diane Wood of the U.S. 7th Circuit Court of Appeals in Chicago is likely to be considered as a possible nominee. She, too, has taught at the University of Chicago Law School, knows Obama and was appointed to the appeals court by President Bill Clinton.

Two other judges who have been mentioned as nominees included Judge Sonia Sotomayor of the U.S. appeals court in New York and Judge Kim Wardlaw of the U.S. 9th Circuit Court of Appeals in California.

During the campaign, Obama did not tip his hand, but when asked about who he admired, he praised Justice Souter as a sensible and reasonable judge who is not ideologue.

Souter’s career will go down in history as one of many justices who proved to be entirely different than what was forecast. When nominated by President George H.W. Bush, he was called a conservative who would vote on the right. John Sununu, Bush’s chief of staff, referred to him as a “home run for conservatives.”

But soon after taking his seat in 1990, it became clear that the White House did not really know its own nominee. In 1992, Souter cast a key vote with Justices Sandra Day O’Connor and Anthony Kennedy to preserve Roe v. Wade and the right to abortion nationwide. And in the years afterward, he voted regularly with the court’s liberal bloc.

This week’s party switch by Pennsylvania Sen. Arlen Specter may also give Obama more leeway in his selection. When Clinton had two vacancies to fill, he chose moderate Democrats, partly in deference to Republicans. President George W. Bush also faced the threat of a potential Democratic filibuster if he chose a nominee who was too far to the right.

If Obama has 60 Democratic votes in the Senate, to be determined by the outcome of Minnesota’s still-pending court challenge over the seat there, he would not face the same threat of a filibuster by Republicans.

© 2009, Tribune Co. Source: McClatchy-Tribune Information Services.