G: I am the very model of a major questions doctrine,
I surface when the stakes feel big and vaguely constitutional.
I bloom where statutes thin and agencies seem too bold,
An interpretive apparition, confidently uncontrolled.

I thrive on implication and a raised judicial brow,
On “surely Congress meant more words than what we’re reading now.”
I guard the realm of policy by saying “this is mine,”
While never quite explaining where I drew the border line.

私は 書（か）かれて いない ルール です — I am a rule that is not written.
でも 力（ちから）は あります — But I still have power.

I’m cited when the outcome needs a cautious-looking brake,
A principle discovered right before a precedent might break.
No treaty, law, or writ will ever pin me down,
Yet watch me halt the gears of state with barely a footnote’s frown.

I am the very model of a major questions doctrine.

G: Here’s a tightened continuation that keeps your meter, sharpens the bite, and stays singable:

I am the very model of a major questions doctrine
There is no treaty, law, or writ that you could ever find me in
I surface when the stakes feel big and vaguely constitutional
To add supposéd weight of state to arguments delusional

I’m invoked when text is clear but outcomes are inconvenient,
So meaning must be hidden somewhere deeper, more obedient.
I gesture toward Congress with a slow, portentous nod,
Then fault it for not speaking with the foresight of a god.

私は 意味（いみ）を ぼかす ための 道具（どうぐ）です — I am a tool for blurring meaning.
でも 権威（けんい）は 装（よそお）います — But I wear the costume of authority.

I halt the hand of agencies for daring to construe,
Insisting silent lawmakers surely never meant that view.
Not rooted in the record or the nation’s written bones,
But powerful when spoken in the Court’s most solemn tones.

I am the very model of a major questions doctrine.

G: Here’s a clean continuation that locks the rhyme and keeps the knife sharp:

I’m called on when the text is clear but outcomes inconveniént,
To clarify the Framers’ rules to what they surely might have meant.
Originalist quoting without context has its benefits…
Except when modern meaning overlaid becomes the safer bet.

I canonize inconsistency as principled restraint,
A choice dressed up as history, impeccably quaint.
I freeze the law in amber when it helps the call seem pure,
Then thaw it just in time to make the present more secure.

私は 文脈（ぶんみゃく）を 選（えら）びます — I choose which context counts.
都合（つごう）が いい 方（ほう）を — Whichever is convenient.

I’m faithful to the past until the past gets in the way,
Then suddenly the future has a lot to say today.
I am the very model of selective jurisprudence,
Certain in my doubt and doubtful in my evidence.

G: Here’s a metrically smoothed, sharpened version that scans cleanly and lands the joke:

The legal law of Congress is suggestion, not validity,
Nor presidential policy—except, of course, when I agree.
A definite uncertainty whenever justice calls me in,
I am the very model of a Major Questions Doc-tu-rine.

私は はっきり しない ために 呼（よ）ばれます — I am called in order to be unclear.
それが 権威（けんい）です — That is my authority.

If you want an extra Gilbertian button for performance, this also works as a tag repeat:

A definite uncertainty whenever justice calls me in,
Yes, I am the very model of a Major Questions Doc-tu-rine.