Why can the Supreme court re-hear cases that have already been decided?

As is the case with this late term/partial birth abortion hearing. I know in criminal court unless substantial evidence has changed, you can not retry a person after a verdict. Why then can the supreme court re-hear a case they've already decided? doesn't that negate their entire purpose?





and please, this question is not about abortion... not interested in abortion opinions right now.Why can the Supreme court re-hear cases that have already been decided?
They cannot. Once a case has been ruled on, that decision is binding (other than appeals to a higher court). It's called ';res judicata'; -- the issue has been decided.





However, there is one limited circumstance. In some rare situations, the Supreme Court (or appellate court) rules on one specific aspect of a case -- say a jurisdictional question, or a procedural issue. The case is then remanded back to the lower courts for further proceedings.





At the end of the trial, either party can appeal on the merits. And if they raise issues on appeal that were not previously addressed, there is the possibility of the case making it all the way back to the Supreme Court for resolution of different issues. Same case, different questions of law being addressed.





As to the partial-birth ban law, that law hadn't been reviewed by the Supreme Court before. The Supreme Court struck down a similar (but not identical) Nebraska state law. Three appellate courts have all struck down the federal law as unconstitutional, but the Supreme Court only reviewed the federal law yesterday.





So, it's not a matter of re-hearing a case that's already been decided. It's a matter of hearing a case that is similar to one that had already been decided. The primary legal issue now to be resolved by the Supreme Court on this case is whether Congress can make legislative findings (';never medically necessary';) that are legally binding when evaluating constitutionality.





If they can, it basically means Congress can make any law pass constitutional scrutiny, just be including legislative findings that effectively order the courts to let the law stand.





{EDIT} The above answers are also correct. Kudos to MLaw for catching the 10-day motion for reconsideration exception as well.Why can the Supreme court re-hear cases that have already been decided?
If you are referring to yesterday's argument on so-called ';partial birth abortion,'; they are NOT re-hearing a case. They are hearing an appeal from a lower court in a new case that happens to involve issues related to those they've heard before.





BYW: Courts CAN rehear cases. Under the Federal Rules of Appellate procedure which apply to the S. CT., and under Federal Rules of Civil Procedure which apply to Federal trial courts, a party can request a re-hearing within 10 days of a final court order to correct errors in law or fact.
No, it considers human error, and has the authority to make things right.
The Supreme Court is the highest appellate court in the United States.





When a case is decided at a trial court, the loser (and sometimes even the winner, if he didn't get everything he wanted) can appeal the ruling to an appellate court. Eventually, it works its way up to the Supreme Court.





While the Supreme Court does have the power to reach down and snatch just about any federal case through a writ of certiorari, it is exceedingly rare.





They don't rehear cases they've decided. They hear a new case with different parties covering the same issue as an old case. If they want to resolve the controversy differently than in a prior case, they'll have to overrule all or part of the prior ruling.
Don't confuse ';Original'; and ';Appelate'; jurisdiction. This isn't a criminal case; it's a case involving the constitutionality of a law. Since the Supreme Court has complete control over its appelate docket there are no limits to how many times it can hear something.





The last time a case like this was before the court the members were different, and the law in question came from another state. The court ruled the way it ruled; but that doesn't preclude the court from changing its mind. So long as five justices (in conference) vote to take the case, there is no limit to the number of times an issue can be brought before the court.