Er, yeah, it is, if you're capable of following an argument down about half a page.
I ask, then, has God rejected his people? By no means! For I myself am an Israelite, a descendant of Abraham, a member of the tribe of Benjamin. God has not rejected his people whom he foreknew. (Rom. 11:1-2)
So too at the present time there is a remnant [of Israel], chosen by grace.... (5)
What then? Israel failed to obtain what it was seeking. The elect obtained it, but the rest were hardened.... (7)
So I ask, did they stumble in order that they might fall? By no means! Rather, through their trespass salvation has come to the Gentiles, so as to make Israel jealous. Now if their trespass means riches for the world, and if their failure means riches for the Gentiles, how much more will their full inclusion mean! (11-12)
if their rejection means the reconciliation of the world, what will their acceptance mean but life from the dead? If the dough offered as firstfruits is holy, so is the whole lump, and if the root is holy, so are the branches. (15-16)
But if some of the branches were broken off, and you, although a wild olive shoot, were grafted in among the others and now share in the nourishing root of the olive tree, do not be arrogant toward the branches. (17-18)
Paul has been talking about Israel since the beginning of the chapter. (The beginning of chapter 9, really.). Israel is the "they" of verse 11 and onward, and the "branches" of the olive-tree analogy. If the branches are Israel, so is the tree.