In the 1906 case Wecker v. National Enameling and Stamping Company, the U.S Supreme Court ruled in favor of Wecker. The case arose when an employee was injured while working at a factory owned by National Enameling and Stamping Company due to faulty machinery that had not been properly maintained or inspected for safety hazards. The company argued that they were not liable for damages because the worker knew about the dangerous condition of the machine but continued to use it anyway, invoking what is known as "assumption of risk". However, this defense was rejected by the court on grounds that assumption of risk does not apply if an employer has violated a statutory duty designed to protect employees from harm - in this instance, maintaining safe equipment. Therefore, even though Wecker may have known about and voluntarily assumed some level of danger associated with his job duties (which would normally absolve employers from liability), he did not assume responsibility for his employer's failure to comply with safety regulations.

In the dissenting opinion for Wecker v. National Enameling and Stamping Company, Justice Harlan argued that the majority's decision was inconsistent with principles of federalism and comity among states. He contended that Missouri courts should have been allowed to decide whether they had jurisdiction over a case involving an injury occurring in Illinois but filed by a plaintiff residing in Missouri. The majority's ruling effectively denied Missouri its sovereign right to interpret its own laws regarding personal injuries sustained outside state borders. Furthermore, he disagreed with the notion that federal courts could intervene simply because there might be prejudice against corporations in state court proceedings; such intervention would undermine faith in state judicial systems' ability to deliver fair judgments. In essence, Harlan believed this decision encroached upon states' rights and disrupted balance between federal and state powers.