Numbers are important at the nine-member high court, in the end maybe more important than the actual arguments lawyers will advance on the constitutionality or unconstitutionality of the healthcare reform law.
Four liberals face off against four conservatives, with moderate conservative Justice Anthony Kennedy most often joining conservatives to form a 5-4 conservative majority. But not always.
If either side manages to get a justice to withdraw -- specifically either Justice Elena Kagan or Justice Clarence Thomas -- it could tip the balance in any final ruling for or against the federal law.
Under attack are two federal laws enacted in 2010 under President Barack Obama's direction, the Patient Protection and Affordable Care Act and amendments to it contained in the Health Care and Education Reconciliation Act.
The principal law contains a number of provisions that profoundly change the health insurance landscape, including a ban against insurance companies dropping people when they get sick, special high-risk pools for those with pre-existing conditions who need insurance, keeping children on their parents' insurance until they finish college, maintaining special insurance for early retirees until they reach Medicare age and a tax credit for small businesses to provide employee insurance.
The most controversial element of reform, the one most under legal attack, doesn't take effect until 2014. By that year, most people will be required to have health insurance or pay a tax.
A number of constitutional challenges to the laws in general and the individual mandate in particular are threading their way through the federal trial and appeals courts. The U.S. Supreme Court is likely to consolidate most of them into one bundle for a combined review.
Supreme Court action is not a done deal, of course.
Republicans could take over both houses of Congress in 2012 and repeal the law and its amendments, making the court cases moot and heading off the legal challenges at the pass. If they took the presidency as well that could solve the problem of overcoming a veto of repeal by Obama.
But that is an exceedingly high hill for the GOP to climb, and the odds the debate will reach the Supreme Court are good. And the justices, as they showed in deciding the 2000 presidential election, are not shy about taking on politically charged questions.
Which brings us back to the numbers.
In her first term on the high court, Kagan withdrew from dozens of cases because of her work as U.S solicitor general. Efforts to get Kagan to "recuse," or withdraw, herself from a prospective healthcare challenge began even before she ascended to the high court.
In an opinion piece published last July 13, The Wall Street Journal noted Kagan, responding to a question in a Senate confirmation hearings, said she had no role in advising the Obama administration on healthcare reform.
At the time Kagan was U.S. solicitor general, the administration's top courtroom lawyer. Federal law requires judges who have served in government to withdraw when they have "participated as counsel, adviser or material witness concerning the proceeding or expressed an opinion concerning the merits of the particular case in controversy."
The Journal said it doubted Kagan's assertion she did not offer a merit opinion to the administration on healthcare reform, adding: "Ms. Kagan would sit as Mr. Obama's nominee on the nation's highest court on a case of momentous constitutional importance. If there is any chance that the public will perceive her to have prejudged the case, or rubber-stamped the views of the president who appointed her, she will damage her own credibility as a justice and that of the entire court."
The attempt to push Kagan out grew more serious when 49 congressional Republicans signed a letter asking for an investigation of her denial of involvement.
The letter, sent to House Judiciary Committee Chairman Lamar Smith of Texas and ranking Democrat John Conyers of Michigan, asked for an immediate investigation by the committee. The 49 Republicans said recently released U.S. Justice Department documents show Kagan "actively participated with her Obama administration colleagues in formulating a defense" for the law.
"Even from the limited number of DOJ e-mails released to date through the Freedom of Information Act lawsuit" by Judicial Watch, the letter said, "it is evident that Justice Kagan was involved in (healthcare reform) defense activities to a degree that warrants her disqualification from related proceedings as specified" by the federal law.
Two Republican presidential candidates, U.S. Rep. Ron Paul of Texas and U.S. Rep. Michele Bachmann of Minnesota, were among the signers.
The Justice Department had a different take on the released e-mails, The Washington Times reported. A department spokeswoman said, "During her tenure, former Solicitor General Elena Kagan did not play any substantive role in litigation challenging healthcare reform legislation, and the documents that were released reflect that."
Wait a minute, Democrats said. If Kagan has to go, what about questions surrounding Clarence Thomas and that anti-healthcare reform money?
Last February, one week after U.S. Sen. Orrin Hatch, R-Utah, called for Kagan to recuse herself, a group of 74 House Democrats called for Thomas to remove himself from healthcare reform review, citing his wife's ties to the Tea Party and other anti-healthcare initiatives.
New York Democrat Anthony Weiner -- remember him? He quit Congress after admitting he tweeted pictures of his crotch to women he didn't know -- led the charge.
"The appearance of a conflict of interest merits recusal under federal law. From what we have already seen, the line between your impartiality and you and your wife's financial stake in the overturn of healthcare reform is blurred," the lawmakers said in their letter, Politico reported. "Your spouse is advertising herself as a lobbyist who has 'experience and connections' and appeals to clients who want a particular decision -- they want to overturn healthcare reform."
Liberty Central, a conservative think tank, was founded by Thomas' wife Virginia to oppose healthcare reform and climate change legislation.
"Conservatives, without a peep of protest, accepted the fact that the wife of a Supreme Court justice was accepting corporate contributions to lead a campaign against the president of the United States on two issues that would ultimately be decided by the Supreme Court," an opinion piece in the Orlando (Fla.) Sentinel said. "But can you imagine what howls of protest would have been heard had Mrs. Stephen Breyer led a similar campaign against George W. Bush?"
The piece cited Think Progress reports the American Enterprise Institute gave Thomas a bust of Abraham Lincoln worth $15,000.
"At the time, AEI was also involved in three cases before the Supreme Court. Thomas recused himself from none of the three," the piece said. "Think Progress was also the first to report Thomas' attendance at a top-secret corporate fundraising conference held in Palm Springs (Calif.) in January 2008 and hosted by (right-wing billionaires) Charles and David Koch."
The letter by the Democratic House members also said Thomas' "failure to disclose Ginny Thomas' receipt of $686,589 from the Heritage Foundation, a prominent opponent of healthcare reform, between 2003 and 2007 has raised great concern."
Wait another minute, liberal Justice Stephen Breyer said at last month's Aspen (Colo.) Ideas Festival.
When an audience member posed a recusal question based on Thomas' situation, The Daily Beast reported, Breyer said, "This is a false issue.
"As far as what your wife does or your husband does, I myself try to stick to a certain principle, and feel very strongly about it, that a wife or a husband is an independent person and they make up their own minds what their career is going to be."
Breyer suggested a Thomas recusal would not be a good idea, The Daily Beast said. "The Supreme Court is different in one respect. In every other court, if I decided in a close matter to recuse myself, that's the easy decision. That's one fewer case I have to decide, and besides, they'll bring in somebody else to decide it. If I recuse myself on the Supreme Court, there is no one else and that could switch the result."
One other thing, Breyer pointed out: That federal law requiring judges to recuse themselves if there is a conflict of interest -- the one prominently featured in the letters from congressional Democrats and Republicans -- doesn't apply to Supreme Court justices.
In the end, whether to withdraw from a case to preserve the appearance of impartiality is strictly an individual justice's choice.
One of the most famous examples of that principle came in 2004, when Justice Antonin Scalia joined Vice President Dick Cheney in a visit to a duck-hunting farm in Louisiana. Besides the disturbing image of Scalia and Cheney waddling around, blasting away at equally plump half-tame ducks, the Supreme Court already had agreed to hear a case on whether Cheney had the right to keep secret the names of lobbyists invited to participate on the administration's energy advisory board.
Scalia angrily rejected broad calls for him to withdraw from the case, eventually joining in a unanimous decision to "duck" the Cheney question and send it back down to the lower courts -- though he wrote separately he would have dismissed the case.
History certainly may repeat itself in any high court review of the healthcare reform challenges.
Bottom line: Don't expect either Kagan or Thomas to withdraw from the case.