Let me make myself clear.
God can override our Free Will, he can make us all do what he wants, he can force us to accept Jesus.
But he chooses not to, he wants everyone to come to him, but he would prefer to accept as his Children only those who want to be his Children.
It has nothing to do with the Sovereignty of God.
Calvinists are a lot like many Atheists and others who reject Christianity all together. They think in order for God to be Sovereign then what does happen must be what he wants to happen.