For God has consigned all to disobedience, that he may have Mercy On All. (Romans 11:32, ESV)
This is a verse I’ve seen used by Universalists and obviously they take the all’s to mean the whole human race without exception. But is this really what the verse teaches after the section of Romans known as God’s Sovereign Choice (Rom 9-11)?
It can be reasonably seen that all here refers to Jews and Gentiles, but not every single one of them that has lived or will live. The earlier chapters (9-11) very well emphasize God’s sovereignty in salvation. God has mercy on whom He wills (Rom 9:15), mercy only comes from God and it’s entirely depended on God (Rom 9:16). It seems then very inconsistent for us to take the all without exception rather than all without distinction.
A brief comment is made by the ESV Study Bible: 
Rom. 11:32 The word all here refers to Jews and Gentiles (all without distinction, not all without exception). The sin and disobedience of both Jews and Gentiles is highlighted, to emphasize God’s mercy in saving some among both Jews and Gentiles.
John Gill writes:
For God hath concluded them all in unbelief,.... Both Jews and Gentiles, particularly God's elect among them: some think the metaphor is taken from the binding up of sheaves in bands; and that Jews and Gentiles are the sheaves, and unbelief the band, in which they are bound together; but the apostle is not speaking of their being together in unbelief, but as separate, first the Gentiles, and now the Jews: rather it seems to be taken from a prison, and Jews and Gentiles are represented as prisoners, and unbelief the prison, in which they are shut up by God: not that God is the author of unbelief, or of any other sin in men; he does not put it into them, or them into that, but finding them in unbelief, concludes them in it, or leaves them in such a state, and does not as yet however deliver out of it, or say to the prisoners, go forth: moreover, to be "concluded in unbelief", is the same as to be "concluded under sin", Ga 3:22; that is, to be thoroughly convinced of it; and to be held and bound down by such a sense of it in the conscience, as to see no way to escape deserved punishment, or to obtain salvation, but by fleeing to the mercy of God in Christ:
that he might have mercy upon all: not upon all the individuals of Jews and Gentiles; for all are not concluded in, or convinced of the sin of unbelief, but only such who are eventually believers, as appears from the parallel text, Ga 3:22; and designs all God's elect among the Jews, called "their fulness", Ro 11:12; and all God's elect among the Gentiles, called "the fulness of the Gentiles", Ro 11:25; for whom he has mercy in store, and will bestow it on them; and in order to bring them to a sense of their need of it, and that he may the more illustriously display the riches of it, he leaves them for a while in a state of unbelief, and then by his Spirit thoroughly convinces them of it, and gives them faith to look to, and believe in, the mercy of our Lord Jesus Christ, unto eternal life. John Gill, Exposition of the Entire Bible