Wright explains what Paul means by “hardening” in Romans 11:7: “What then? Israel failed to obtain what it was seeking. The elect obtained it, but the rest were hardened…” citing then Deut 29:4; Isa 29:10 and then Psalm 69:22-23. What does “hardening” mean?
Wright: “This apocalyptic context of ‘hardening’ is vital; ignoring it leads interpreters either into abstract discussions of predestination and reprobation or into the idea of a temporary ‘hardening,’ which is then reversed.”

What does it mean then? It is what “happens during a temporary suspension of the judgment that would otherwise have fallen, to allow time for some to escape.” For Paul, it permits Gentiles and Jews like Paul to believe in the Messiah. That is, “unbelieving Israel is hardened permanently.” This does not mean individuals can’t or don’t respond for they can and they do.
He sees this at an ethno-national level and not comprehensive of each and every Jew.