The "both sides" thing is (should be) unnecessary. None of these mentally ill shooters are representing a political party or a mainstream ideology. Just because one shooter votes for Bernie Sanders and the other votes for Donald Trump doesn't mean this is Democrats v. Republicans or Liberals v. Conservatives. It is actually the 99% of us v. the relative handful of people who have the right combination of irrational, anti-social and dangerous thoughts, access to weapons, the capacity to plan, and the will to carry the plan to fruition. Their political views provide them only the requisite thread of distorted rationale to justify their anger and their actions. They aren't on a "side".
That said, there is not a shred of doubt in my thinking that today's political climate has increased the heat of anger in such souls, and the selective vitriol of the rhetoric provides targets for those seeking aim for their rage. Trump isn't an equal partner in the dance, but he is responsible for stepping up the tempo. He is the leader of this band for at least two more years and I am worried that as the heat continues to turn up in Washington, the disturbed among us will be increasingly triggered.