In the case of Howat et al. v. State of Kansas, 1921, the U.S Supreme Court upheld a decision by the state court to convict and sentence union leaders for contempt after they violated an injunction during a coal strike in southeast Kansas in 1919-20. The defendants argued that their actions were protected under federal labor laws and that only federal courts had jurisdiction over such matters. However, the Supreme Court ruled that states have authority to enforce their own laws regarding public safety and welfare within their borders unless explicitly prohibited by Congress or if it interferes with interstate commerce regulation - neither condition was found applicable here. Therefore, even though there were existing national labor relations policies favoring peaceful negotiation between employers and employees, these did not preclude states from taking necessary measures to maintain peace and order during strikes or other industrial disputes.

In the dissenting opinion for Howat et al. v. State of Kansas, Justice McReynolds disagreed with the majority's decision to uphold state court jurisdiction over violations of a federal injunction issued by a federal district court during labor disputes. He argued that such an approach would undermine the authority and supremacy of federal courts in matters within their purview under U.S Constitution’s Article III, Section 1 which vests judicial power in one Supreme Court and inferior courts as Congress may establish. The justice contended that allowing state courts to punish contempt against orders from federal courts could lead to conflicting interpretations and enforcement actions between different jurisdictions, thereby creating confusion and potential injustice for defendants who are subject to these rulings. Furthermore, he warned this might encourage forum shopping where litigants choose a particular court because they believe it will provide them with more favorable outcomes rather than on jurisdictional grounds or merits of their case.