The U.S. Supreme Court case National Credit Union Administration v. First National Bank & Trust Co., et al., 1997, revolved around the interpretation of a clause in the Federal Credit Union Act (FCUA) that defined who could join a credit union. The FCUA stated that membership was limited to groups with a "common bond," which had been interpreted by the National Credit Union Administration (NCUA) to mean multiple unrelated employer groups could belong to one credit union as long as each individual group shared an internal common bond. However, banks and other financial institutions challenged this interpretation, arguing it allowed credit unions unfair competitive advantages by expanding their potential customer base beyond what was intended by law. In its decision, the Supreme Court sided with the banks and ruled against NCUA's interpretation of "common bond." It held that federal credit unions were restricted from enrolling members outside of their specific employee group(s), thus limiting their ability to expand membership across different organizations or industries.

In the dissenting opinion for the case of National Credit Union Administration v. First National Bank & Trust Co., Justice Thomas, joined by Justices Scalia and Souter, argued that the majority had misinterpreted the Federal Credit Union Act (FCUA). The dissenters believed that under a proper reading of FCUA's text and structure, credit unions should be limited to serving groups with a common bond of occupation or association. They disagreed with the majority's view that multiple unrelated employer groups could form a single credit union without sharing any commonality beyond their membership in said union. According to them, this interpretation was inconsistent with Congress’s intent when it enacted FCUA in 1934 as well as its subsequent amendments to limit expansion and competition among financial institutions. Furthermore, they criticized NCUA’s policy allowing virtually unlimited expansion of federal credit unions’ field-of-membership as an overreach not supported by statutory language.