Final answer:
The bias in favor of existing decisions or precedents in the legal system is known as stare decisis, a principle ensuring stability and consistency in law but with flexibility for change.
Step-by-step explanation:
The term for the bias in favor of precedents or existing decisions is known as stare decisis. This legal doctrine translates to "to stand by things decided" from Latin. Stare decisis is a foundational principle in the United States' common law system that instructs judges to make rulings based on precedent, ensuring consistency and stability within the legal system.
Judges identify similarities between current and past cases to appropriately apply the law, guided by the rationale that today's decisions become tomorrow's precedents. However, this principle allows for some flexibility and evolution of law as courts, particularly the Supreme Court, have on occasion overturned precedent to address changes in societal values or correct legal injustices.