Politics surely has a lot to do with it. I have some theories. But I'd better stick with what I know best, and what you need to learn about a.s.a.p. They find themselves in a never-ending struggle to keep those awful emotions at bay. Now they are on the dishing-out side.
Bullies feel truly safe only when they are engaged in making someone else feel truly un safe.
Their own inner world calms down briefly while they are shaking up someone else's. They never get enough. They must constantly reassure themselves that now, they are the party in control. It's a true addiction. Naturally they gravitate to fields that give them an opportunity to indulge this addiction.