JPMorgan Chase & Co.

Bernie and the big banks

Bernie and the big banks

The recent kerfuffle about Bernie Sanders purportedly not knowing how to bust up the big banks says far more about the threat Mr. Sanders poses to the Democratic establishment and its Wall Street wing than it does about the candidate himself.

Of course Mr. Sanders knows how to bust up the big banks. He's already introduced legislation to do just that. And even without new legislation, a president has the power under the Dodd-Frank Act to initiate such a breakup.

But Mr. Sanders threatens the Democratic establishment and Wall Street, not least because he's intent on doing exactly what he says he'll do: breaking up the biggest banks.

The biggest are far larger today than...