We know that when referring to constitutional amendments or clauses, we capitalize the clause or amendment. Thus, our First Amendment has a Free Exercise Clause, and an Establishment Clause. Our Fourteenth Amendment contains a Due Prcoess Clause and an Equal Protection Clause. But what do we do when referring to more than one clause at a time? Do we write: She filed suit under the Equal Protection and Due Process Clauses <or clauses>? Bryan A. Garner provides the answer:
When a common noun is part of a proper name, capitalize it when the entire name appears <Mississippi River>, but not when it is separated from the proper name <the Mississippi and Missouri rivers>.
Bryan A. Garner, Garner's Modern American Usage at 128.
Now we know what to write: She filed suit under the Equal Protection and Due Process clauses.
You are probably also wondering why I capitalize Constitution, but not constitutional. Again, Garner tells us why:
Capitalize the adjectival form of a noun that is always proper <Keynesian economics> but not one from a noun that can also be common <congressional investigation>.
And so, for purposes of this rule, we would write: Strip searching non-violent misdemeanor arrestees is not a constitutional policy.
Consider buying Garner's American Usage. If you read good books, your writing is probably grammatical. But we all get stuck (or get into arguments over usage) and thus need a final arbiter. Even if you have perfect insticts and thus never have a question on usage the book is still valuable since it explains why you write what you do. Finally, Minor Wisdom and Evan endorse it.