Aside from rabbinical Jews and Dispensationalists, there is no dispute on this teaching. Those Jews and Gentiles joined to Christ are God's only chosen people.
You don't have to worry about what Darby said about anything...You need to be concerned about what God said about it...
Rom 11:25 For I would not, brethren, that ye should be ignorant of this mystery, lest ye should be wise in your own conceits; that blindness in part is happened to Israel, until the fulness of the Gentiles be come in.
UNTIL the fulness of the Gentiles be come in...
Isreal has been cut off UNTIL something happens...They have been blinded...But not forever...
Rom 11:26 And so all Israel shall be saved: as it is written, There shall come out of Sion the Deliverer, and shall turn away ungodliness from Jacob:
Rom 11:27 For this is my covenant unto them, when I shall take away their sins.
God still has a covenant with Israel that was cut of from the roots of the tree...
Rom 11:28 As concerning the gospel, they are enemies for your sakes: but as touching the election, they are beloved for the fathers' sakes.
God is not done with Israel...
Rom 11:29 For the gifts and calling of God are without repentance.
God has called Israel to inherit the land...God will not repent from that covenant...And that covenant was never given to the church...We have no need nor interest in the land given to Israel...
God has called Israel to inherit the land...God will not repent from that covenant
Sigh.
You simply don't understand Covenants, nor the fundamental doctrines of Redemption.
FWIW, the "land promise" was fulfilled in the days of Joshua, David and Solomon. Other than the demonstrated foolishness of the Darbyites, I can't see why you are looking for an encore, particularly since your personal definition of Israel hasn't bothered to keep their end of the deal up for the last two millennia.
To clear up this problem for you, I would strongly recommend reading O Palmer Robertson's "The Israel of God: Yesterday, Today and Tomorrow". I'm certain the "Left Behind" Cabal would surely resent you doing that.
They are cut off until they are regrafted by faith to spiritual Israel, the Church.
God has called Israel to inherit the land...God will not repent from that covenant...And that covenant was never given to the church...
It is misleading to keep repeating this promise while covering up the requirement for a reciprocating faithfulness that is unfulfilled by Jews outside the Church.