Is the Lord omnipotent or not?

Jeremiah 32:27 and Judges 1:19

1. (Jeremiah 32:27) - "Behold, I am the Lord, the God of all flesh; is anything too difficult for Me?"
2. (Judges 1:19) - "Now the Lord was with Judah, and they took possession of the hill country; but they could not drive out the inhabitants of the valley because they had iron chariots."
3. (Titus 1:2) - "In the hope of eternal life, which God, who cannot lie, promised long ages ago."

In Jeremiah 32:27 God is speaking about His might and sovereignty.  God can do anything He wants to do.  In Judges 1:19, the Lord was indeed with Judah, but the fact that Judah could not drive out the inhabitants of the land does not mean that God couldn't do it.  God often uses people and takes their failures into account when carrying out His ultimate plan.

Titus 1:2 tells us that God cannot lie.  Of course, this is not a contradiction since God cannot violate His own nature of purity.  So when God says he can do anything, He does not mean that He can do those things that are contrary to what He is.