The courts
circuit split
Two or more federal appeals courts reading the same federal law differently, so it means different things in different regions. The strongest reason for Supreme Court review.
In full
Because each circuit's precedent binds only its own territory, an unresolved split leaves identical conduct lawful in one state and unlawful in another. Petitions for certiorari lead with the split for exactly that reason. The Supreme Court's main institutional job is keeping federal law uniform, and splits are the queue.
Where to go next
Keep going
Browse every term in the glossary, or see the vocabulary in motion in the How government works walkthroughs.
A plain-language explanation for civic education, not legal advice. When in doubt, the official source named above controls.