I have seen many a Laertes who is playing this line throughout the whole scene – or the whole play, even. He’s fiery and ready to burst most of the time. But – a more interesting Laertes gets himself to this moment with lots of ups and downs. He may be fighting with himself for a good long while before he’s pushed to behaving this badly.
As much as we see Laertes break the rules (by staging a coup, breaking down doors, leaping into graves, etc) – he seems to have a strong sense of honor and this move is well outside the bounds of that. I think he’d need to feel pushed well past his own tolerance to make a move like this.
He probably has had to silence his conscience in a number of ways to step outside of the confines of the game this way.
And I feel like the crowd should know it, too. They need to have a response that suggests that Laertes has broken through rules and honor and codes to go after Hamlet in an aggressive out of bounds move.
The Hamlet Project 