I would argue that we citizens of Michigan bear some responsibility for these events. If you had asked me even when I was a small child if the country schools had a good chance of producing kids with the same kind of education and critical thinking skills as the city schools I would have told you that's not possible. The only way that things like this can be prevented from happening again is by reinvesting in our educational infrastructure and providing the children of assault rifle wielding bumpkins with more and better education.
That's pretty much Elizabeth Warren's argument, yeah. The fundamental problem is that one political party benefits when the majority of the populace is uneducated, fearful and deprived. The other benefits when the majority of the populace is educated, empathetic and secure. The former party has historically supported wealth concentration while the latter party has historically supported wealth distribution. Stable equilibrium has been destroyed and both parties are weak. That's how we got here.