[This is the 2nd of a 3-part piece, in which I suggest that Pharaoh displayed behavior typical of abusers, by (1) becoming irrationally angry to an excessive degree when faced with a perceived affront to his pride and (2) being adamantly unwilling to release his hold on those he was abusing — even to the point of hurting himself]:
An abuser could even be lured into a death-trap by fury at (perceived) affronts to his pride.]
For example, in “The Godfather,” “Sonny Corleone” is furious at the beating of his sister, “Connie,” by her husband, “Carlo.” Having previously warned Carlo to control himself (true to form, by humiliating him via a vicious public beating), Sonny was actually furious at the insult to his own sense of control. He was protecting his own fractured self-esteem; not his sister’s physical well-being.
Using “gallantry” as a façade, “Sonny” uses his sister “Connie’s” beating as an excuse to furiously pursue “Carlo.” “Sonny” has no better way of handling insults than to become infuriated to the point of disregarding his own safety – because to be concerned with his own safety would be (in his eyes, at least) an act of weakness. Leaving in fury, without any protection, Sonny is lured to his own brutal assassination. Carlo, himself an abuser, who had been treated as an “inferior” within the inner circle of the Corleone Family, has been irrationally drawn into this dangerous plot as an accomplice – which ultimately results in his own death, as well – by Sonny’s affronts to his own low self-esteem.
We easily recognize the psychological truth this represents.
The “makkot” — plagues — were the same kind of affront to Pharaoh’s irrational pride that Carlo’s beating of Connie had been to Sonny’s. For Pharaoh and Sonny, the “danger” to their “pride/ ego” is heirarchically worse than the danger to their actual bodies!
At the same time, an abuser can refuse to allow the demeaned partner – of whom he/she is so critical and belittling – to leave, because to do so is to be faced with the very sense of powerlessness that the abuser fears most. Also, the abuser loses control (or the illusion of it) over the other in the exact moment that the other makes an independent decision. It’s therefore not uncommon for the victim of abuse to hear themselves told, “You’ll leave when I say you can leave;” “If you leave, I’ll kill you;” or, using a subtler maneuver of control: “If you leave, I’ll kill myself.”
If abusing is a way for the abuser to maintain “self-esteem” and a sense of control, it’s also a form of self-medication.
Giving the abuser at least a momentary sense of control, abusing increases his/her self-esteem, thereby temporarily discharging and relieving some of the pent up tension and fear. What the abuser really seeks is that “good feeling,” with no concern at all for how it is achieved or the effects of his/her behavior on others. “Abusing” therefore resembles other addictive behaviors.
Perhaps, then, Pharaoh pursued the Israelites in a desperate, irrational attempt to bring homeostasis to his self-esteem, after the seemingly intolerable damage he perceived to have been done to it by the plagues and, especially, by the departure of the Israelites.
It suggests the following meaning of “I will harden Pharaoh’s heart”: Pharaoh, perceiving the request to release the Israelites as an affront to or attack upon his self-worth, will reflexively try to return it to its “set point” by attempting to re-assert control over the situation.
It could further mean that G-d was saying, “It will be impossible to free the Israelites without Pharaoh perceiving it as an attack on his own worth. His heart will therefore be ‘hardened’ in automatic response.”
Rabbi Hertz says the same: “The Omniscient G-d knew beforehand whither his obstinacy would lead Pharaoh, and prepared Moses for initial failure by warning him that Pharaoh’s heart would become ‘hardened’.”  One might say, “Pharaoh’s heart will be hardened by My command to let the Israelites go” or “…will become hardened in response to My command.”
In his time, Pharaoh was the most powerful human being in the world; leader of the most technologically advanced nation of that time. To the extent that we, today, base our own self-esteem on riches, love, success (or “winning”), material possessions, glory, etc., Pharaoh stands as the prime example of one who had, in overwhelming abundance, everything that we desire for ourselves, yet still lacked an unassailable sense of self-worth.