This is the second in a set of questions that I received recently. I spoke to the question more directly in a private response. I'm going to let myself respond a little more broadly here.
I'm struggling with understanding why God hardened Pharaoh's heart so many times when Moses was petitioning for his people's freedom. Someone told me that the word used means to twist or wrench. They explained that God was revealing the true intentions of Pharaoh. What's your take?
Let's start with what the word means. I've never heard or read about it meaning "twist" or "wrench." A lot of study remains in the meaning of Hebrew words but I'm not aware of any study of this word. Its broad meaning is more focused on "strengthening" and that concepts has multiple applications. So it can mean to seize, be severe, to strengthen (make firm/display strength), etc. It is within this category that we can certainly arrive at the general idea of "true intention." This hardening could be God displaying His power through Pharaoh or it could be God strengthening Pharaoh's self-righteous and sinful resolve. I do believe that both of these meanings could be found to be contextually relevant to Exodus 4:21.
It is here that my particular perspective on the Calvinistic idea of Total Depravity is best understood. From a theological perspective, God most certainly did not reveal anything other than the true desire and intention of Pharaoh. Put another way, nothing God did went against the natural will of Pharaoh and his desire to sin against God. But I would also say that this desire to sin was predestined from before creation.
Typically, the questions concerning salvation/regeneration in the Protestant tradition have not struggled with the idea that mankind is basically evil. Even the most popular form of Arminianism (Wesleyan) affirms a solid and extensive doctrine of Original Sin. Admittedly I've been influenced by John Piper significantly with regard to this subject. But it is my view that every act of our heart may not be "morally evil" but if it is never done in faith with the intent of glorying God hence it is sin (Rom 3:23; 14:23; Heb 11:6). This is the full breadth of "total depravity." I am less excited about a fallen nature or depraved substance of man because I find these concepts to be more consistent with a Gnostic view that must ultimately be discouraged. I acknowledge them but I am timid to express how corrupt those natures are without disparaging God's creation.
Back to the application with Pharaoh. In my view, Pharaoh is an example of God amplifying the desires of Pharaoh's sinful, faithless heart instead of softening it through the grace of His Holy Spirit (Eze 11:19; 36:26). Pharaoh was no more depraved or "fallen" than we are. God's grace is required in our lives so that we do not become modern Pharaohs of our own sin and rebellion.