WASHINGTON (CNN) -- Chief Justice John Roberts expressed "complete confidence" Saturday in his Supreme Court colleagues to fairly decide whether to remove themselves from hot-button cases such as health care reform -- a timely election-year issue that has created a judicial and political headache for the nine-member court.
Roberts made his comments in his annual Year-End Report, issued as part of his role as head of the entire federal judiciary. In doing so, the 56-year-old chief justice gently and indirectly tried to address -- and perhaps dampen-- calls from politicians and activists on the left and right that two justices withdraw from hearing perhaps the most important issue the high court has confronted in a decade.
Oral arguments will be held in March over the constitutionality of the sweeping health care law championed by President Barack Obama. Justices Clarence Thomas and Elena Kagan have been called upon to recuse from hearing and ruling on the series of five cases brought by a coalition of 26 states, and other groups.
Roberts focused nearly all of his 16-page report explaining the court's own internal rules, which allow each individual justice to decide for themselves whether to stay in a case.
"The Supreme Court does not sit in judgment of one its own members' decision whether to recuse in the course of deciding a case," he said of his fellow benchmates. "They are jurists of exceptional integrity and experience whose character and fitness have been examined through a vigorous appointment and confirmation process. I know that they each give careful consideration to any recusal questions that arise."
The chief justice did not mention any justice by name, or discuss the current, specific recusal questions over health care. If he had commented directly on the ongoing controversy, there could have been demands that he, too, withdraw from hearing the healthcare issue.
The Code of Judicial Conduct is binding on all other federal judges, except the Supreme Court -- a distinction that has long been a source of criticism in political and legal circles. Those policies on recusal, financial disclosure, and receipt of gifts and outside income are a matter of public record, and are maintained by the Judicial Conference, the policy-making body of the lower federal courts. The code was first adopted in 1924.
The justices have long consulted those ethics rules as matter of course, and 20 years ago decided internally to unofficially follow the same rules as other judges. But Roberts acknowledged that unlike other judges, recusal decisions by the nine justices are not reviewable by any court.
"A justice accordingly cannot withdraw from a case as a matter of convenience or simply to avoid controversy," said Roberts, who joined the court in 2005. "Rather, each justice has an obligation to the court to be sure of the need to recuse before deciding to withdraw from a case." He also said separation of powers limits any interference from the legislative and executive branches on such matters.
Thomas, 63, has been criticized for attending meetings sponsored by conservative legal groups, and for failing for years to report his wife's income. Virginia "Ginni" Thomas has long been an outspoken conservative political activist who recently formed a group tied to the tea party movement. She also has been critical of the health care law.
Liberal groups have demanded the justice stay out of the health care appeals.
Kagan's service as the solicitor general in the Obama Justice Department also has drawn scrutiny. Some conservatives have said she was more deeply involved in formulating legal strategy over health care than the administration has acknowledged.
The legislation was working its way through Congress around the same time last year when she was being considered for the high court. The White House has repeatedly said the 51-year-old justice was "kept out of the loop"-- not consulted or otherwise involved in defending the law while solicitor general.
Neither Thomas nor Kagan has indicated they would recuse, and some legal analysts say the issue is more about politics than anything else. One fewer justice could mean a 4-4 tie that would fail to establish constitutional precedence on an issue as important as health care reform, and the power of the federal government to regulate such a massive social and financial enterprise as medical care.
In general, recusal is required -- according the federal law -- in any case where the judge's "impartiality might be reasonably questioned." Each judge or justice has a good deal of discretion to handle such questions as they see fit.
Roberts noted the high court is technically exempt from being forced to follow the Code of Conduct. The Constitution only specifically mandated "one supreme Court," while Congress later created the lower federal courts.
"Because the Judicial Conference (instituted by Congress) is an instrument for the management of the lower federal courts," Roberts said, "its committees have no mandate to prescribe rules or standards for any other body," meaning the Supreme Court.
Translation: the justices comply with the same Code of Conduct other judges do, but by choice, not by force of law.
"The justices serve on the nation's court of last resort," said Roberts of its unique role. If the high court were ever to ultimately decide whether a fellow justice should stay in a pending appeal or not, "it would create an undesirable situation in which the court could affect the outcome of a case by selecting who among its members may participate."
Past year-end reports from the chief justice have focused on budget cutbacks, frozen salaries, rising caseloads, and court security.