If God decided to turn these, too from their sin, why wouldn't they also be part of God's elect?
Then all would be saved because no one can stay God's hand. But God did not do this.
The problem with most folks about predestination is that they don't believe mankind is 'dead in trespasses and sin'. They don't believe how bad Psalm 14 and 53 (and quoted by the Apostle Paul in Romans 3) is even though this is repeated 3 times in Scripture that None sought Him on their own, None Understood God on the own, and None did Good on their own.
Instead they believe mankind is spiritually sick and not dead and able to save themselves through their choice; man earninging His salvation through His choice. This gives man the glory and makes man the center of His faith (which is self centered and not good).
Whereas believing that mankind is dead in trespasses and sin means that God has to do major work before the new birth. He basically has to do a spiritual heart transplant and a reprogramming of the mind so that the person can love Him and hold faith in the persons brain (into which God gives a measure: See Romans 5:12).
God also gives 'ears to hear' and 'eyes to see' the things of God. So that when the preacher preaches the Word to him he will hear, and seeing such that he can see the Word for himself- be convicted of his sin (now that he has a heart and mind able to do so) and to confess the faith that God has planted inside him - going from Darkness into Life. Since God does this, the believer later can give him all the glory since there is no way he or she could have done it. With the doctrine of salvation by choice, man gets the glory and can unchoose God later on a whim and loose his Salvation.
Whereas if God has done everything necessary for faith and salvation then to Him belongs all the Glory and all the Praise.