The popular saying is always assume good intentions. Use that on your friends, co-workers, and family.
It doesn't really work with really terrible situations. Instead, mix it up a bit to make it more fun. I like to come up with stories for people who do bad things that they have some random weird secret intentions.
This ugly obnoxious lady who jumped the queue here is secretly an alien from some galaxy far away trying to learn the ropes of human etiquette.
Donald Trump is secretly trying to expose all the flaws of US governmental system, in order to rebuild towards a better system; One which cannot be destroyed by a single incompetent leader.
This f****ng asshole who just punched my face has heroically saved 100 lives last year and committed himself to balance it off with random bursts of violence this year.