I smell replacement theology.
No, it's a simple reading:
Rom 9:4 Who are Israelites; to whom [pertaineth] the adoption, and the glory, and the covenants, and the giving of the law, and the service [of God], and the promises;
Rom 9:5 Whose [are] the fathers, and of whom as concerning the flesh Christ [came], who is over all, God blessed for ever. Amen.
Rom 9:6 Not as though the word of God hath taken none effect. For they [are] not all Israel, which are of Israel:
Rom 9:7 Neither, because they are the seed of Abraham, [are they] all children: but, In Isaac shall thy seed be called.
Rom 9:8 That is, They which are the children of the flesh, these [are] not the children of God: but the children of the promise are counted for the seed.