[Just another Joe]

If I'm a cashier at a store and I harangue every shopper about the evils of Obama, my employer has a right to fire me. I'm crazy if I think that can't happen.

Ah, but if you're a cashier at a store, harangue everyone you see on your own time, and have an exemplary work record does your employer have a right to fire you because you espouse your political views in public but in no way associate them with your workplace?

[ClearCase_guy]

Firefighter Mike Di’Giacomo said his SUV is banned from in the firehouse because the bumper stickers he has on it, displays his political views.

I think this guy is associating his political views with his workplace. And his employer is saying "Please don't".