If we read Romans 9-11 in the traditional Reformed way, which creates an absolute division between the predestined elect and the predestined reprobate, we repeat the error that Paul is at pains to correct between the Jewish interlocuter and himself in chapters 1-3. There the Jews are shown, in no uncertain terms, to be in no better position that the "sinner" Gentiles, as the historical unfaithfulness to the Law is tantamount to having no Law in the first place. So, Paul asks, is God the God only of the Jews? Or of the Gentiles as well? Is He the Savior of only the chosen people? Or of the whole world?
Paul's further argument is that all "in Adam" (that is, all humanity, regardless of ethnic descent) "shall be made alive" in Christ.
Why would, then, Paul do an about face in chapters 9-11 and argue that, in fact, God is the God of the elect, the Savior of the elect, and not of the reprobate? Especially since he frames it in the same terms of ethnic descent as he did in chapters 1-3 (the beginning piece about wanting himself to be damned to save his countrymen, the Jacob-Esau dichotomy, "all Israel shall be saved")? Could it be that he is looking to the Old Testament Scriptures, not some theoretical eternal predestinating decree, and seeing Israel being called 'elect' and showing that, in fact, they've misunderstood election and, instead, "God has consigned all [Jew and Gentile] to disobedience, so that He might have mercy on all"?