Last year, as Sen. Arlen Specter reviewed the nomination of Elena Kagan to be solicitor general, he was frustrated. As the senior Republican on the Judiciary Committee, Specter concluded that the Harvard Law School dean had ducked questions that he saw as important for senators to cast an informed vote on her nomination. He voted against her confirmation.

Today, Kagan is on the widely circulated short list to replace retiring Justice John Paul Stevens on the Supreme Court. Should she get the nod, she's likely to continue to avoid questions that she contends might come before the court. And a lack of responsiveness by any nominee is almost certain to be a line of attack used by critics trying to shoot a nomination down.

That scenario puts the ever-irascible Specter in an unusual spot since he switched parties last year to become a Democrat. Today, he faces a difficult bid to be re-elected to a sixth term. Might he seriously consider a vote against President Obama's nominee to the Supreme Court?

When asked whether Specter would oppose her nomination if Kagan were the nominee and again avoided responding to questions, Kate Kelly, his press secretary, responded in an e-mail: "Senator Specter will thoroughly review any nominee from President Obama on the merits. It's premature to prejudge any candidate for Supreme Court Justice."

But last year, as he took to the Senate floor to debate Kagan's nomination on March 19, Specter was adamant that ducking by nominees should prompt a "no" vote. He noted that he had gone to "substantial length, really great length, to find out about Dean Kagan's approach to the law and approach to the job of solicitor general and to get some of her ideas on the law because she is nominated to a critical public policymaking position."

He had a lengthy one-on-one "courtesy visit" in his office with her, he grilled Kagan at length during the Judiciary hearing, and he followed up with written questions. Despite that "long process," the Pennsylvania lawmaker concluded, "I still don't know very much about Dean Kagan."

Though Specter conceded that she would be confirmed notwithstanding his objections -- as she was on a 61-31 vote -- he said that the institutional role of the Senate to examine nominees and be fully informed was at stake. He even said an unnamed executive branch official tried to dissuade him from pursuing certain lines of inquiry.

"I am not prepared to relinquish the institutional prerogatives of the Senate to ask questions," declared Specter. "The executive branch nominees want confirmation. Well, senators want information to base their opinions on."

He proceeded to ask Kagan about some specific cases, including one in which victims of the 9/11 terrorist attacks had sought damages from Saudi Arabia, Saudi princes and a banker, who allegedly funded Muslim charities that then provided support for Al Qaeda. The district court and the Second Circuit Court of Appeals dismissed the claims because they found the defendants were immune from being sued. The Supreme Court had asked the Solicitor General's Office for its view of whether the court should hear the case on appeal.

"I am unfamiliar with this case," Kagan said. She made clear what was obvious -- namely, that "a critically important part of this process would be to" work with the State Department and the Department of Justice.

Specter was unimpressed. "Well, we do not know very much about her views from that answer," he said during the debate on the floor. "There has been a lot of information in the public domain that Saudi charities were involved. Fifteen of the 19 hijackers were from Saudi Arabia. People were murdered. There are claims pending in court. The question is whether the Supreme Court is going to take the case. Well, I wish to know what the nominee for the position of solicitor general thinks about it."

Specter described similar parrying by Kagan when he asked her about other cases. The 80-year-old lawmaker said that he and Kagan disagreed about the extent to which a nominee must be responsive to lawmakers' questions. Kagan refused to provide more detailed answers, Specter said, because she said it would be "inappropriate" because the case was pending.

Specter disagreed. He made clear that he was not tilting at windmills even though he said he had "no illusion the issues I have raised will prevail. I think it is pretty plain that Dean Kagan will be confirmed. But I do not articulate this as a protest vote or as a protest position, but one of institutional prerogatives. We ought to know more about these nominees. We ought to take the confirmation process very seriously."

Fast-forward to today. It is a fair guess that Kagan, if nominated, will argue she would be even more constrained in her testimony since so many questions might come up in future cases before the court. And other nominees have similarly ducked senators' questions since Robert Bork's nomination was defeated in 1987 after he provided very detailed explanations of his controversial views only to find that his answers provided ammunition for his critics to label his views as out of the mainstream.

Still, even as Specter contends that it is "premature" to take a stance on a nominee, he has repeatedly made clear his unhappiness about nominees running for cover when asked what he sees as legitimate questions. Indeed, in his book, Passion for Truth, published a decade ago, Specter wrote that the Senate "should resist, if not refuse, to confirm Supreme Court nominees who refuse to answer questions on fundamental issues."

But the political realities for Specter have changed. As Obama campaigns for him and helps him in his fight in an upcoming Democratic primary, it appears to be a safe bet that, in the end, whether a nominee is responsive or not, the Pennsylvania senator will vote "aye" to confirm the president's choice to fill Stevens' seat.