Washington ? When a Supreme Court nominee such as Judge Sonia Sotomayor comes before the Senate for confirmation, she is promised a full, fair hearing. In fact, every nominee’s path is booby-trapped by the history of previous confirmation battles.

After Justice Samuel Alito was nominated in 2005, Democratic Sen. Mark Pryor of Arkansas, then a very junior member, remarked to me that he was struck by a recurring phenomenon. When discussing the pending confirmation with veteran colleagues, Pryor said, “we may start out talking about Alito, but pretty soon they’re talking about Robert Bork,” the Ronald Reagan nominee who was rejected by the Senate in 1987 after a bitter three-and-a-half month debate.

The Bork battle was historic; a sharp ideological fight that saw interest groups on both sides mobilize as if it were a presidential campaign. When it was over, the conservative jurist — like Sotomayor a veteran Circuit Court judge — complained that when judicial nominees “are treated like political candidates,” with searching examination not just of their credentials, but of their ideology and views on controversial issues, the effect is “to erode public confidence in the impartiality of courts, and to endanger the independence of the judiciary.”

The scars of Bork’s 33-hour cross-examination before the Judiciary Committee had not healed 18 years later when Chief Justice John Roberts and Alito both came up for confirmation.

This week, I asked Pryor if he thought we were due for another replay with Sotomayor. “I hope not,” he said. “I think the country has moved way beyond Bork, and I hope the Senate has.”

One thing that may make it harder to forget the partisan and ideological battles of the past is that President Obama found reasons to oppose both the Bush nominees, Roberts and Alito, in the only Supreme Court confirmation tests during his four years of Senate service.

The chief justice has told friends that he was disappointed by Obama’s vote against him, because he thought they had had a meeting of minds. Indeed, in his floor speech on Sept. 22, 2005, Obama said, “I am sorely tempted to vote for Judge Roberts based on my study of his resume, his conduct during the hearings and a conversation I had with him yesterday afternoon.

“There is absolutely no doubt in my mind Judge Roberts is qualified to sit on the highest court in the land. Moreover, he seems to have the comportment and the temperament that makes for a good judge. He is humble, he is personally decent and he appears to be respectful of different points of view.

“It is absolutely clear to me that Judge Roberts truly loves the law … that he does, in fact, deeply respect the basic precepts that go into deciding 95 percent of the cases that come before the federal court — adherence to precedence, a certain modesty in reading statutes and constitutional text, a respect for procedural regularity, and an impartiality in presiding over the adversarial system. All of these characteristics make me want to vote for Judge Roberts.”

The problem, Obama said, comes in the last 5 percent — the cases where “precedent and rules of construction” are not enough and where justice “can only be determined on the basis of one’s deepest values.” The rights of women, minorities, the disabled are dependent on those cases where “the critical ingredient is supplied by what is in the judge’s heart.”

Obama said Roberts’ record on women’s rights and racial issues was not good enough to answer the doubts about his “deepest values.”

Obama was undoubtedly right that a judge’s values — and experiences — will be crucial in some of his or her decisions on the bench. Roberts’ favorite analogy of an umpire calling balls and strikes is much less accurate. Justices have many more borderline calls; look at the frequency of 5-4 decisions.

Based on the Obama precedent, the White House can hardly complain if Republicans push beyond the question of Sotomayor’s qualifications and examine her values — and her biases.

Some day, the Senate may again be satisfied to examine only professional credentials, recognizing the uncertain dynamics of a nine-person bench. But while the Bork and Obama precedents live, that is not likely.