In the 1941 case of Brillhart, Administrator v. Excess Insurance Company of America, the U.S. Supreme Court ruled that federal courts have discretion to abstain from hearing declaratory judgment actions even when they have jurisdiction over such cases. The dispute arose after a car accident involving three parties and multiple insurance companies led to conflicting claims about liability coverage amounts under different policies. When one insurer sought a declaratory judgment in federal court regarding its obligations, another party argued that state probate proceedings were already addressing these issues and thus the federal action was unnecessary and duplicative. The Supreme Court agreed with this argument, holding that principles of judicial administration and efficiency allow for restraint in exercising jurisdiction over declaratory judgments where parallel state court proceedings exist.

In the dissenting opinion for Brillhart v. Excess Insurance Company of America, Justice Frankfurter argued that federal courts should not abstain from deciding cases within their jurisdiction simply because a similar case is pending in state court. He contended that such an approach undermines the purpose and function of diversity jurisdiction, which aims to provide litigants with an impartial forum when they are involved in disputes crossing state lines. Furthermore, he emphasized that it's essential for federal courts to exercise their lawful authority unless there are exceptional circumstances justifying abstention. In this particular case, he saw no compelling reason why the district court should have declined to decide on its merits.