Carl Schmitt's book on Hamlet is pretty cool. He tries to steer between psychological readings of the play and readings that completely reduce it to historical happenstance.
I'm surprised by how "literary" it is. That is, there are political questions which I felt sure he would immediately gravitate to that he sets aside. He focuses on why the precise character of the Queen's guilt is opaque and on the figure of the "avenger."
"The first question that presents itself to every spectator and listener concerns the participation of the mother in the murder. Was she aware of the murder? Did she even perhaps instigate it? Did she, before the murder, have relationship with the murderer or only after?"
"What should a son do if he wants to avenge his murdered father but in the process comes up against his own mother, now the wife of the murderer...a son who is caught in this way in a conflict between the duty of vengeance and the bond to the mother..."
Hamlet can either kill the murderer and mother Orestes style, or team up with mom, and kill the murderer as in the Nordic Amleth myth. Without the guilt of the mother being resolved, Shakespeare avoids both of these poles.
This leads Schmitt to look at history. The husband of Mary Q of Scots is murdered and Mary marries the murderer 3 months later. Shakes is having a tough time under Q Elizabeth and needs James (the son of Mary) to ascend to the throne...
So, Shakespeare is compelled to be delicate about Queen Gertrude who parallels Mary, in order to stay in the good graces of her son James for when he eventually ascends to the throne, which he does, and which secures Shakespeare his previous advantages.