Washington ? Conservative interest groups and Republican lawmakers want Justice Elena Kagan off the health care case. Liberals and Democrats in Congress say it’s Justice Clarence Thomas who should sit it out.

Neither justice is budging — the right decision, according to many ethicists and legal experts.

None of the parties in the case has asked the justices to excuse themselves. But underlying the calls on both sides is their belief that the conservative Thomas is a sure vote to strike down President Barack Obama’s health care law and that the liberal Kagan is certain to uphold the main domestic achievement of the man who appointed her.

The stakes are high in the court’s election-year review of a law aimed at extending coverage to more than 30 million people. Both sides have engaged in broad legal and political maneuvering for the most favorable conditions surrounding the court’s consideration of the case.

Taking away just one vote potentially could tip the outcome on the nine-justice court.

Republican lawmakers recently have stepped up their effort against Kagan, complaining that the Justice Department has not fully revealed Kagan’s involvement in planning the response to challenges to the law. Kagan was Obama’s solicitor general, the administration’s top Supreme Court lawyer, until he nominated her to the high court last year.

“The public has a right to know both the full extent of Justice Kagan’s involvement with this legislation while she was solicitor general, as well as her previously stated views and opinions about the legislation while she was serving as solicitor general,” the House Judiciary Committee chairman, Rep. Lamar Smith, R-Texas, said Tuesday in a letter to Attorney General Eric Holder.

Democrats have said Thomas has a conflict of interest stemming from the work of his wife, Virginia, with several groups that opposed the health care overhaul.

“From what we have already seen, the line between your impartiality and you and your wife’s financial stake in the overturn of health care reform is blurred,” 74 Democrats wrote Thomas in February. The lead writer was Anthony Weiner, the New York Democrat who resigned from Congress in June over his use of Twitter to send explicit photos of himself to women.

One lawmaker who signed the letter, Rep. Louise Slaughter, D-N.Y., said she feels even more strongly now that Thomas has a conflict. She wants the Justice Department to investigate Thomas for omitting his wife’s employers, including the Heritage Foundation and the tea-party linked Liberty Central, from his annual financial disclosure reports.

The campaigns against the justices are partisan, suggesting to some legal experts that the complaints are less about perceived conflicts than the outcome of the health care case.

“They are not doing it in the dark about how they think the justices will rule,” said University of Notre Dame law professor Richard Garnett.

Looking at the claims made against Thomas and Kagan, Garnett said, “I don’t think there’s really a plausible case that either of these two justices should feel the need to recuse themselves.”