What is the proper procedure for handling situations in which jurisdictional and merits facts overlap?

QUESTION PRESENTED In Steel Co. v. Citizens for a Better Environment, 523 U.S. 83, 101, 118 S. Ct. 1003 (1998), this Court emphasized that a federal court must first establish as “an antecedent” matter that it has jurisdiction. The circuits are split, however, as to how to handle situations where jurisdictional and merits facts overlap. The Fourth and Fifth Circuits interpret Bell v. Hood, 327 US. 678, 66 S. Ct. 773 (1946) to support a general rule that a federal court must assume (without deciding) jurisdiction and proceed to the merits. The majority circuits interpret Steel Co. more strictly to require determination of jurisdiction first, but even they disagree as to whether a federal court should apply a lower standard of proof for the jurisdictional determination (as the Third Circuit holds), or whether the standard should vary based upon the stage of the case (as the First Circuit holds). The question presented is: In light of the Steel Co. rule that jurisdiction must be determined as “an antecedent” matter, what is the proper procedure for handling situations in which jurisdictional and merits facts overlap.