From the introduction of the brief:

Since the founding of our nation, states have limited interest rates as the primary protection against predatory lending. Evasions of usury laws are as old as the laws, but courts consistently look beyond form to the substance of the transaction to prevent subterfuge.

Ever since banks were provided with legislative exemptions from state usury laws, nonbank lenders have tried to use “rent-a-bank” arrangements to avoid state interest rate laws. But courts look beyond the nominal bank that funded and put its name on a loan, holding that state usury laws apply to the true lender and are not preempted by federal law. The purported validwhen- made theory is irrelevant when the true lender is not a bank. Moreover, unambiguous statutory language, legislative history, and caselaw, all show that federal law does not preempt state usury laws as applied to nonbank assignees.