The best answer? Justice Nelson's concurrence in Dred Scott v. Sandford.

This article focuses on the concurring opinion of Justice Samuel Nelson in the 1857 U.S. Supreme Court case Dred Scott v. Sandford, arguing that Nelson’s legal reasoning has been underappreciated compared to Chief Justice Roger Taney’s majority opinion and the dissents by Justices McLean and Curtis. Nelson concurred in the judgment against Dred Scott but rejected Taney’s broader constitutional claims, grounding his opinion in established legal doctrines of state sovereignty over personal status and conflict-of-laws principles, particularly the binding authority of the Missouri Supreme Court’s decision. Unlike Taney’s politically charged and racially exclusionary reasoning or the dissenters’ novel assertions of federal judicial review over state law, Nelson’s approach adhered more closely to accepted jurisprudence of the time and avoided overt partisanship. The article further notes that Nelson’s opinion carried political prudence by limiting judicial overreach and that it influenced subsequent Northern court decisions affirming state authority over slavery status within their borders. Overall, Nelson’s concurrence is presented as the most legally coherent and politically moderate response among the Court’s opinions in the Dred Scott case.