(CNSNews.com) – Ronald Rotunda, a law professor and expert on legal ethics, says that Supreme Court Justice Elena Kagan must be recused from judging the challenge to President Barack Obama's health care law that will be heard by the Supreme Court early next year.

“I think she really has to be disqualified,” Rotunda said at a forum in Washington, D.C., on Tuesday that was hosted by Judicial Watch.

Rotunda is the Doy & Dee Henley chairman and distinguished professor of jurisprudence at Chapman University. He testified about the legal basis for Supreme Court recusals at Kagan's confirmation hearings and is the co-author of one of the most widely used textbooks on legal ethics, Problems and Materials on Professional Responsibility. He is also the co-author of Legal Ethics: The Lawyer's Deskbook on Professional Responsibility.

At Tuesday's Judicial Watch forum, Rotunda was joined by Judicial Watch President Tom Fitton, and Carrie Severino, chief counsel and policy director of the Judicial Crisis Network.

Prior to being confirmed to the Supreme Court, Kagan served as the Obama administration's solicitor general, with the job of defending the administration's position in federal court cases. While she was solicitor general, the Obamacare law was proposed, debated, threatened by lawsuits, enacted and, in fact, targeted by lawsuits filed by multiple states...