In the Lehmann v. State Board of Public Accountancy case in 1923, the U.S Supreme Court ruled on a dispute involving professional certification for accountants. The plaintiff, Mr. Lehmann, was an experienced accountant who had been practicing his profession in California without any formal certification or license from the state's Board of Public Accountancy. When new legislation required all practicing accountants to be certified by this board, Lehmann challenged it as unconstitutional and discriminatory since he would have to stop working until he passed their examination while those already licensed wouldn't need to take it. The court disagreed with him and upheld the law stating that states have broad powers under their police authority to regulate professions such as accounting for public welfare purposes including ensuring competency through licensing exams. They also found no discrimination because everyone had equal opportunity to apply for licensure regardless of prior experience or lack thereof.

In the dissenting opinion for Lehmann v. State Board of Public Accountancy, the justice argued that the majority's decision was an overreach of judicial power and a violation of states' rights to regulate professions within their borders. The justice contended that California had a legitimate interest in ensuring accountants practicing within its jurisdiction were competent and ethical, which justified its requirement for out-of-state accountants to pass an examination before being granted licenses. He also pointed out that there was no evidence showing this regulation disproportionately affected non-residents or discriminated against them unfairly. Furthermore, he disagreed with the majority's interpretation of the Privileges and Immunities Clause, arguing it did not guarantee individuals from one state could practice any profession they chose in another without meeting local licensing requirements. Instead, he believed it only protected citizens from discrimination based on their state residency status when seeking basic civil liberties or essential economic activities.