Physical Danger
Political scientists don't have dangerous jobs. Getting a staple stuck in your hand can be painful; your butt might fall asleep while you stare deep into the eyes of a Twitter feed. These things aren't life-threatening.
But one thing to remember about politics is that they can bring out the very worst, as well as the very best, in some people. There's a reason metal detectors and the fuzz are posted at government buildings. There's a reason the President is surrounded by men in black.
As a political scientist, you're not likely to get shot or blown up or tied to the railroad tracks. You are likely, at some point, to email with, talk on the phone to, or encounter in person someone who is angry or just flat-out insane. When that happens, you need to be prepared on how to react.