I've seen people claim that this section is not talking about the persons of Jacob and Esau, but the nations.
10 And not only this, but when Rebecca also had conceived by one man, even by our father Isaac 11 (for the children not yet being born, nor having done any good or evil, that the purpose of God according to election might stand, not of works but of Him who calls), 12 it was said to her, “The older shall serve the younger.” 13 As it is written, “Jacob I have loved, but Esau I have hated.”
("the children") is added to the text, but you can't avoid not yet being born nor having done any good or evil. He's talking about Jacob and Esau, not the nations. It can be further applied to the nations, but the context is clearly about the unborn Jacob and Esau. And again, “Jacob I have loved, but Esau I have hated” is clearly about the two individuals.
Why is this important? Because the point is "that the purpose of God according to election might stand", which says that God made the choice before they were even born.
Romans 9
That
the Gentiles, who did not pursue righteousness, have obtained it, a righteousness that is
by faith; 31 but the people of
Israel, who pursued the law as the way of righteousness, have not attained their goal. 32 Why not? Because they pursued it not by faith but as if it were
by works. They stumbled over the stumbling stone. 33 As it is written:
“See, I lay in Zion a stone that causes people to stumble
and a rock that makes them fall,
and the one who believes in him will never be put to shame.
The above is the same teaching in Romans 3 below :
Romans 3
But now the righteousness of God has been manifested apart from law, although the law and the prophets bear witness to it, 22 the righteousness of God through faith in Jesus Christ for all who believe. For there is no distinction; 23 since all have sinned and fall short of the glory of God, 24 they are justified by his grace as a gift, through the redemption which is in Christ Jesus, 25 whom God put forward as an expiation by his blood, to be received
by faith. This was to show God’s righteousness, because in his divine forbearance he had passed over former sins; 26 it was to prove at the present time that he himself is righteous and that he justifies him who has faith in Jesus. 27 Then what becomes of our boasting? It is excluded. On what principle? On the principle of works? No, but on
the principle of faith. 28 For we hold that a man is justified by faith apart from works of law. 29 Or is God the God of Jews only? Is he not the God of Gentiles also? Yes, of Gentiles also, 30 since God is one; and he will justify the circumcised on the ground of their faith and the uncircumcised
through their faith.
And if we keep reading into chapter 9 the hardened Jew/reprobate is whom Paul prays for in their temporary hardening until all the gentiles are grafted into the branch. The potter/clay is God using the hardened Jews- His elect,chosen people ( destruction ) to bring in non elect vessels of glory ( gentiles) their salvation. The potter/clay is another analogy that contradicts calvinism, not support it. Once the glasses/lens are removed one can see the passages in their greater biblical context and harmonize them.
Conclusion : it’s nations not individuals from the context
Romans 9:30–32 (ESV) — 30 What shall we say, then? That Gentiles who did not pursue righteousness have attained it, that is, a righteousness that is by faith; 31 but that Israel who pursued a law that would lead to righteousness did not succeed in reaching that law. 32 Why? Because they did not pursue it by faith, but as if it were based on works. They have stumbled over the stumbling stone,
Romans 10:18–21 (ESV) — 18 But I ask, have they not heard? Indeed they have, for “Their voice has gone out to all the earth, and their words to the ends of the world.” 19 But I ask, did Israel not understand? First Moses says, “I will make you jealous of those who are not a nation; with a foolish nation I will make you angry.” 20 Then Isaiah is so bold as to say, “I have been found by those who did not seek me; I have shown myself to those who did not ask for me.” 21 But of Israel he says, “All day long I have held out my hands to a disobedient and contrary people.”
Romans 11:19–23 (ESV) — 19 Then you will say, “Branches were broken off so that I might be grafted in.” 20 That is true. They were broken off because of their unbelief, but you stand fast through faith. So do not become proud, but fear. 21 For if God did not spare the natural branches, neither will he spare you. 22 Note then the kindness and the severity of God: severity toward those who have fallen, but God’s kindness to you, provided you continue in his kindness. Otherwise you too will be cut off. 23 And even they, if they do not continue in their unbelief, will be grafted in, for God has the power to graft them in again.
hope this helps !!!