ABC News explains:
In many ways, the Schiavo case has become a civics lesson on judicial review. The way the American legal system is structured is such that the trial is when the facts of the case are argued. It's the only shot each side has at arguing the facts in the case. Once the jury or a judge makes a decision on the facts, those findings are generally not relitigated absent extraordinary circumstances.
In the appeals process that follows, the judges decide only whether or not what happened in the previous court was correct under the law -- that the interested parties have received due process under the law. While several courts have determined that Terri's case did receive due process, the Schindlers this week are asking for emergency injunction -- in essence a chance to buy some more time -- to make their arguments again. The judicial test for an injunction is that the requesting party prove that they have a substantial claim, explains Goldblatt.
What's really bizarre is the fact that the politicians who voted for the extraordinary law giving Terri's parents the right to go to federal court also seem to have thought that they would get a new trial. They of all people should have been aware of the fact that the federal courts will only look at whether Terri Schiavo's case was accorded due process and whether any of her rights were violated. That's the difference between trial courts and appeal courts.
Terri Schiavo's case has already gone through the trial courts and at every stage the judges have found in favor of Michael Schiavo. Every appeals court that has looked at the case has found that the trial courts acted properly and that there is no reason to hold a new trial.
Of course, some have argued that the extraordinary law that sent Terri's case to the federal courts was created solely so that Republicans would have a new basis for attacking judges and the judicial system. The howls and screams from Christian Right extremists are already becoming deafening, despite the fact that conservative judges appointed by Republicans have been just as likely to rule in favor of Michael Schiavo as anyone else.