I don't think there's a "Constitutional right of Habeus Corpus", per say. Rather, motions of habeus corpus are brought when people's other rights (e.g. reasonable bail, speedy trial, etc.) are denied.
IMHO, the right Terri was denied was the right of due process. Due process in criminal cases requires that the accused be allowed counsel (and have counsel provided if unable to supply it themselves). I see no reason why a civil case that could result in someone's death should have any less of a requirement.
I'm going to guess it was Gary Amos, in commentary accompanying his article, "Dred Scott and Terri Schiavo."
In all my years dealing with constitutional law, I have always said no to judicial impeachment even when from time to time on various issues some conservative activists have argued for it in specific situations. I can generally provide people more arguments against impeachment than for it where judges are concerned. Sometimes I cannot provide arguments for impeachment at all, because all the valid arguments from my point of view mitigated against judicial impeachment in those situations.
The Schiavo matter is dramatically different. Not only am I convinced that judicial impeachment applies here, I am convinced that it applies to every federal judge in the chain from the district court judge who first received the case under the act signed by President Bush, through the appeals judges of the 11th Circuit, to all nine sitting members of the U.S. Supreme Court, with the exception of the one or two judges that bucked the system.
This is the first time in my several decades of dealing with constitutional law that such a situation exists. I never imagined that I would see this situation in my entire lifetime or in my professional career.
-- Statement continued at the linked site...