Supporters of Kagan such as Walter Dellinger, the acting solicitor general during the Clinton administration, responding in Slate that Greenwald's analysis was "way off the mark." Dellinger pointed in part to Kagan's sharp criticism in 2007 of the Bush administration's "unsupported legal opinions" used to justify violations of federal laws regulating wiretapping and interrogation.
"I do think it is important," Dellinger wrote, "to set the record straight on Elena Kagan's views of presidential power: Her views are fundamentally progressive. "
Human rights advocates have been furious that as solicitor general Kagan has supported some of the same policies held during the Bush administration, including the argument against extending habeas rights to detainees held in Bagram Air Force base.
But experts caution about reading too much into the positions Kagan has taken while serving as solicitor general.
"Part of the reason why it is difficult to look at the solicitor general for the court is because one can't ever really tell, unless they were in the room, whether she is shaping policy, or merely enforcing it," said law professor Stephen I. Vladeck of American University Washington College of Law. "It's unfair to reach any conclusions based purely on external, public indicia."
Obama has made clear his desire to hold confirmation hearings by early July. In her last appearance before Congress, Kagan was a lively witness, at times charming conservative senators. But a confirmation hearing for a lifetime appointment to the court is sure to entail more pointed questions and a closer review of her record.
Kagan may also have to explain comments she made in a 1995 book review on Senate confirmation fights: "When the Senate ceases to engage nominees in meaningful discussion of legal issues, the confirmation process takes on an air of vacuity and farce, and the Senate becomes incapable of either properly evaluating nominees or appropriately educating the public."
She will also be asked more questions about decisions she made while working in the Clinton White House. The administration has yet to release any documents from that time period.
During her confirmation hearings for solicitor general, she was asked about several memos that she prepared in 1987 for her then-boss Justice Thurgood Marshall. Conservatives believe the memos on criminal procedure reveal Kagan to be left of the political spectrum.
At her hearing, Kagan downplayed the effect of the memos, saying, "You know, I was a 27-year-old pipsqueak, and I was working for an 80-year-old giant in the law, and a person who, let us be frank, had very strong jurisprudential and legal views."
"I first looked at that memo, thought about that memo for the first time in 20 years, I suppose, just a couple of days ago when it was included on a blog post. And I looked at it and I thought, 'That is the dumbest thing I have ever heard,'" Kagan said.
Sen. Arlen Specter of Pennsylvania asked her about one memo involving the Adolescent Family Life Act, which authorized federal funds for religious organizations designed to discourage teen pregnancy. Specter, then a Republican who has since become a Democrat, quoted Kagan's memo: "It would be difficult for any religious organization to participate in such projects without injecting some kind of religious teaching."