How does Francis Turretin respond to the fact that in Romans 9:11 Paul quotes from Genesis 25:23 wherein the election of Jacob and Esau related to national blessings, rather than individual salvation? "The answer is although that announcement may be extended to the posterity also (Gen. 25:23; Mal. 1:3) and, in the historical sense, may be referred to the blessing or external appointment to dominion or servitude, still this does not hinder it from being referred (in a mystical sense) properly to election and reprobation with respect to the fathers themselves."
I agree that Paul was using the OT examples of Jacob and Esau to teach more than national election. But I think pointing out that in the OT the passages were national does a lot to blunt the idea that Romans 9 is obviously Calvinistic. Turretin has to retreat to a mystical sense, which inherently seems more prone to be open to a range of interpretations. If Jacob and Esau were just types, how do we know they were types of unconditional individual election and reprobation rather than types of God's promise vs. works? After all, the lead in context seems to strongly indicate that God planned to save via God's promise, not nationality or works.