With time running out to block U.S. Supreme Court nominee Elena Kagan, Republicans appear increasingly divided over whether they have a realistic shot at stopping her confirmation.

Many Republicans say confidentially that it's doubtful even a full-court press by the National Rifle Association and a GOP filibuster could derail Kagan. The Senate Judiciary Committee is expected to approve the nomination Tuesday and send it to the full Senate for a vote.

Curt Levey, executive director of the conservative Committee for Justice organization, says it probably isn't realistic to expect a GOP filibuster.

Levey expects that ultimately four to five GOP senators will vote to confirm her nomination, despite reservations about her lack of trial experience, her views on partial-birth abortion, and her opposition to on-campus military recruitment at Harvard due to the don't ask, don't tell policy on gay armed-service personnel.

Republicans in the Senate, Levey says, appear to lack the will to torpedo Kagan.

"They're not sure what the end game is," Levey says. "They're not going to defeat her, so their feeling is 'Let's just get it over with.' I think if properly played, you could score a lot of political points with it. But I just don't see the will there."

Other conservatives, however, believe the announcement by the National Rifle Association that it will score the Kagan vote due to her stance on gun issues could scare off enough Democrats from red and purple states to put the confirmation at risk.

The best and perhaps only chance Republicans have of stopping Kagan stems from the National Rifle Association's decision last week to score the vote on the nomination.

The NRA says Kagan has failed to demonstrate adequate support for the Second Amendment right to bear arms. The association will mark down any senator who sides with Kagan.

According to Rick Manning, a former NRA lobbyist who now serves as director of communications for the libertarian-leaning Americans for Limited Government organization, there are nine Democratic senators from states whose electorates strongly support the right to bear arms who may have to choose between keeping their coveted "A" rating from the NRA, or voting for Kagan.

They include: Sen. Harry Reid of Nevada, Sen. Max Baucus of Montana, Sen. Mark Begich of Alaska, Sen. Robert Casey of Pennsylvania, Sen. Tim Johnson of South Dakota, Sen. Ben Nelson of Nebraska, Sen. Jon Tester of Montana, Sen. Mark Warner of Virginia, and Sen. Jim Webb of Virginia.

Those senators are no doubt hoping Republicans opt not to filibuster the nomination, a decision that largely rests in the hands of McConnell.

Without a filibuster, many of them would never have to endanger their "A" rating from the NRA with a vote for Kagan. The NRA is calling on its members to contact their senators and urge them to vote against confirming Kagan.

Reid, the majority leader could release some senators — perhaps including himself, given his ongoing battle for re-election — from casting a vote that would draw the NRA's ire, because once the danger of a filibuster is over a simple majority of the Senate is enough to approve the nomination.

If, however, McConnell does order a filibuster, it would take 60 votes to shut off debate.

Although Democrats can probably count on a few GOP defections in a cloture vote, the requirement for 60 votes means many more vulnerable Democrats from swing states would lose their perfect NRA rating.

Manning believes it could be so unpalatable for Reid politically that he might implore the White House to delay the vote until the lame duck session of Congress. It could force the administration to withdraw the nomination, he says.

But Manning's not sure GOP leaders would be willing to go that far.

"They've been against having filibusters for nominees in the past. It would be using the tactics that the Democrats threatened against them in the past... so they're trying to avoid that," he says. "It's not an easy decision for Sen. McConnell to make. But I believe there are compelling reasons to make it."

Levey says a more realistic objective is to get 37 to 40 senators to vote against Kagan -- compared to the 31 senators who voted against the confirmation of Supreme Court Justice Sonia Sotomayor. Levey says that would send a message to President Obama that any future left-of-center nominees are subject to defeat.

"You want to signal that you could stop a future nominee, and you want to use some of the issues that she's vulnerable on both to stain the president and to affect close Senate races in red and purple states," says Levey.

Levey tells Newsmax he does not believe defeating Kagan's nomination is "within the realm of possibility."

One prominent Republican, Harvard law professor Charles Fried, who served as solicitor general in the Reagan administration, went public Monday to warn that GOP opposition against Kagan for political reasons is a big mistake.

He says Kagan is independent minded and is probably about the best nominee Republicans could realistically expect.

"I think it's just awful to take a very, very good nominee and shoot her down because it's an election year, because she isn't a Republican -- of course she isn't!" Fried tells Newsmax. "But she is about as independent as you could expect, as independent as you could imagine a Democrat president nominating."

Fried predicts that Kagan will occasionally side with the Republican members of the Court if she believes they are right.

GOP officials, meanwhile, continue to disseminate talking points for why Kagan's nomination should be defeated. Among them:

• Her apparent support for gun control. As a clerk for Justice Thurgood Marshall, Kagan wrote in 1987 that she was "not sympathetic" to a challenge to the District of Columbia gun ban. In her confirmation hearings, Kagan pointed out the law "was very different" then regarding state and municipal regulation of gun ownership.
• Her "political advocacy." This is the reason McConnell cited for his decision to vote against Kagan. She served in the Clinton administration and was appointed U.S. Solicitor General by President Obama. Republicans say Kagan has spent more time practicing politics than practicing law.
• Her lack of experience. Kagan arguably has less actual legal experience than any nominee in modern times. She toiled for about two years in private practice as a young attorney, and about 14 months as Solicitor General.
• Her position on partial-birth abortion. Americans United for Life has issued a 54-page report on Kagan's role in the decision by then-President Bill Clinton to veto a congressional ban on partial-birth abortion. After reading the report, Sen. Jeff Sessions, the pro-life Republican from Alabama, suggested Kagan had misled senators about her role during her testimony. Kagan appeared to position herself as a neutral party giving advice to President Clinton. Sessions said Kagan "persuaded" Clinton to veto the ban. On Monday, former U.S. Surgeon General C. Everett Koop announced he also opposes Kagan's nomination due to her stance on partial-birth abortion.
• Her stance on military recruitment. Republicans charge Kagan discriminated against military recruiters by forcing them to conduct their activities off campus grounds when she was the dean of Harvard Law School. Kagan called the military's "don't ask, don't tell" policy a "moral injustice of the first order." Kate Obenshain, vice president of the conservative Young America's Foundation, said Kagan had "repeatedly trampled on the rights of patriotic students."
• A liberal bias as Solicitor General. Conservatives charge that Kagan as U.S. Solicitor General had a double standard about which laws to defend. She did not aggressively defend laws that supported the federal government's authority to keep violent offenders in prison for example, they say.
• Her judicial role models. Kagan has expressed unabashed admiration for judges that conservatives consider bad judicial models, such as Justice Marshall and liberal Israeli Justice Aharon Barak. Respected legal scholar Judge Robert H. Bork called Barak possibly "the worst judge on the planet."

The Judiciary Committee vote on Kagan's nomination was originally scheduled for one week ago, but GOP members were granted a one week delay.

Levey predicts all 12 of the Democrats on the committee will vote to confirm Kagan. He expects at least six of the seven Republicans on the panel to oppose her nomination. He says the lone possible Republican vote on the committee to confirm her may come from Sen. Lindsey Graham of South Carolina.

Democrats say they hope to have Kagan confirmed as early as the first week in August.