WASHINGTON (AP) — Supreme Court nominee Elena Kagan embarks on her quest for Senate confirmation with a strong presumption of success, drawing praise from majority Democrats and nary the threat of an all-out election-year battle from Republicans.

GOP critics laid down a series of markers, though, making clear they will question the 50-year-old solicitor general about her lack of judicial experience, her decision as dean of the Harvard Law School to ban military recruiters from campus, and her ability to rule objectively on cases involving the Obama administration.

Americans “do not want someone to be a rubber stamp for any administration,” Senate Republican leader Mitch McConnell said Monday, a few hours after President Barack Obama named Kagan as his choice for the high court. “They instinctively know that a lifetime position on the Supreme Court does not lend itself to on-the-job training.”

Vice President Joe Biden, in interviews Tuesday morning on television news shows, predicted that Kagan would win Senate confirmation with “strong, bipartisan support.”

If confirmed, Kagan would take the place of retiring Justice John Paul Stevens and, on the face of it, would not be expected to alter the ideological balance of a court that often splits 5-4 on the most contentious cases.

Even so, Obama e-mailed a video to thousands of supporters in which he said the 90-year-old Stevens has helped justices “find common ground on some of the most controversial and contentious issues the court has ever faced.” He added Kagan could “ultimately provide that same kind of leadership,” suggesting she had the legal acumen and personality necessary to knit together a majority coalition of five justices, as Stevens has done.

The president did not identify any of the cases he was referring to. But Stevens has been on the majority side in recent years in divided court decisions that ruled detainees at Guantanamo had a right to go to court to challenge their confinement, struck down Bush-era military commissions, and banned the death penalty for offenders younger than 18.

Other close cases where Stevens either wrote the opinion or assigned it as the senior justice on the prevailing side cheered environmentalists and supporters of abortion rights. One directed the Environmental Protection Agency to regulate greenhouse gas emissions from cars and trucks. Another struck down a Nebraska state law that banned a type of late-term abortion.

Obama doesn’t face the voters until 2012, but his decision to videotape a message to his supporters underscored the political context inherent in Kagan’s selection.

While the economy, terrorism and recent passage of health care legislation in Congress are likely to dominate the campaign, Kagan instantly became an issue in the race for the Democratic senatorial nomination in Pennsylvania.

There, Rep. Joe Sestak challenged Sen. Arlen Specter to explain why he had opposed Kagan’s appointment as solicitor general last year, and added the incumbent “may backtrack from his earlier vote” to try to gain support.

Specter said later the two jobs are “distinctly different” from one another, and noted Kagan’s “exemplary credentials.”

Specter was a Republican when Kagan last came before the Senate, and in public remarks at the time, said he opposed her appointment because she had ducked numerous questions.

It wasn’t the only criticism Kagan drew from Republicans when she was seeking approval to become the solicitor general — essentially the president’s lawyer before the Supreme Court.

Her decision to bar military recruiters on campus drew criticism from Sen. Jeff Sessions, R-Ala., who said at the time of her earlier appointment that she had “placed her own opposition to military policies above the need of our military men and women to receive good legal advice, even from Harvard lawyers.”

On Tuesday Sessions said Republicans would have a hard look at Kagan’s record during her year as solicitor general as they consider her nomination.

“Her record is very thin, there’s no doubt about that,” Sessions said on ABC’s “Good Morning America.”

Seven Republicans voted to confirm Kagan, who was approved as solicitor general on a 61-31 vote. At least two of them, Sens. Jon Kyl of Arizona and Orrin Hatch of Utah, emphasized Monday that they would approach her appointment to a lifetime job differently than a political post.

For the most part, Republican-aligned outside groups responded mildly to the nomination, and their attitude as her confirmation hearings approach could help shape the party’s response.

Obama, in his announcement, said he hoped the Senate would confirm Kagan in time for her to join the court before the opening of the next term in October.

To accomplish that, senators would need to vote before leaving the Capitol for their Labor Day vacation, a timetable that Sessions, the leading Republican on the Judiciary Committee, said “should be doable.”

McConnell, the GOP Senate leader, sounded less certain about that.

“Fulfilling our duty to advise and consent on a nomination to this office requires a thorough process, not a rush to judgment,” he said.

But Democrats were already looking ahead to her approval.

Said Sen. Harry Reid of Nevada, the majority leader: “When Solicitor General Kagan is confirmed, the Supreme Court will have three sitting female justices for the first time,” calling that “a historic occurrence that is long overdue.”

___

AP writer Mark Sherman contributed to this report.