This article looks like a good start for an explanation of the killer's motives: Alleged CEO Shooter Luigi Mangione Was Radicalized by Pain. It's remarkable that he wasn't an extremist and that his fans are from all over the political map.
In this climate, the Democratic Party should be deeply ashamed that they lost the election to a billionaire CEO who tried to abolish Obamacare, and this time said he had 'concepts of a plan' to replace it, which will make access to health care even worse.
the democrats have shown over and over they are out of touch with common folk.. I don't see them turning this boat around anytime soon to be honest. But maybe, the wrench in the gears that is Trump is precisely what America needed to rebuild an actual democracy. But first, it has to burn to the ground.