MBE Rules · Constitutional Law
Vagueness doctrine
The rule
A law is unconstitutionally vague under the Due Process Clause if a person of ordinary intelligence cannot understand what conduct is prohibited or if the law invites arbitrary and discriminatory enforcement. Heightened vagueness scrutiny applies to laws touching on First Amendment activity or imposing criminal penalties.
In plain English
Two vices: fair notice + enforcement discretion. Any statute — not just speech-related — can be attacked as vague, but the standard is toughest for laws burdening expression or imposing criminal liability.
The trap
Confusing vagueness (unclear terms) with overbreadth (too much protected conduct swept in). A statute can be one, the other, or both.
Drill this rule until it can't fail you.
Vrenberg generates unlimited questions on this exact rule, tracks your mastery of it, and brings it back until it sticks.