ABC's Jilian Fama and Meghan Kiesel report:

Tomorrow is decision day for the Supreme Court on the constitutionality of the Affordable Care Act, a.k.a Obamacare, and the controversial individual mandate included within it. What kind of decision will SCOTUS hand down? Though no one can be certain, predictions abound:

Lawrence Tribe, Harvard Law School professor who taught both Obama and Chief Justice John Roberts, has faith in Obamacare: "I think it will be upheld in its entirety."

Robert Reich, former Secy. of Labor, is optimistic: "It will uphold the constitutionality of the Affordable Care Act (Obamacare) by a vote of 6 to 3."

Nancy Pelosi, House minority leader, thinks that the courts will rule in favor: "I'm predicting 6 to 3 in favor."

Tom Goldstein, publisher and contributor to SCOTUSblog, says the mandate will not be invalidated: "In the end, you have to make a prediction and take responsibility for it. I believe the mandate will not be invalidated tomorrow. Far less important, I expect the principal opinion will be written by the Chief Justice; a majority of the Court will find it has jurisdiction; and the challenge to the Medicaid expansion will be rejected."

The American Bar Association published a special report devoted to the Supreme Court ruling on health care reform. Eighty-five percent of those surveyed (journalists, lawyers and academics) are predicting that the court will uphold the law.

Michael Tomasky, special correspondent for Newsweek/ The Daily Beast and a contributor to the New York Review of Books, believes SCOTUS is a group of "politicians in robes," thinks the court will carefully declaw Obamacare: "That means overturning the mandate 5-4. But it means doing so narrowly, carefully, almost regretfully."

Ed Whelan, contributor to National Review Online, read the tea leaves before making his prediction: "The fact that Justice Scalia read his dissent from the bench in the Arizona immigration case leads me to believe that the Court will invalidate the individual mandate by a 5-4 vote."

Walter Dellinger, Slate contributor, thinks it's unlikely that mandate will fall: "Now, health care. My gut tells me the court will do something that will be a partial victory for both sides of the seemingly unbridgeable chasm between supporters and opponents of Obamacare."

Check back tomorrow for the latest on the final ruling. In the meantime, see our infographic on the options for how the court could rule.

Get more pure politics at ABC News.com/Politics and a lighter take on the news at OTUSNews.com