Just that a subcommittee can start with the assumption of guilt, with the trial being more or less just a formality towards pronouncing that verdict. The Senate has no requirement for the sort of due process that we are used to for criminal courts, as an impeachment is not a criminal case.
Which is still extremely vague. After a bit of Googling, it seems to me that Claiborne & those removed from office since then had the opportunity to defend themselves & deserved their fate-
Impeachments of Federal Judges | Federal Judicial Center
Biographies of judges include birth/death, Article III judicial service, other federal judicial service, education, professional career, research resources, and other information…

Kangaroo court not found.