I assume "political opinion" as in "the way you vote", not so much speech about politics (which would just be protected by rights protecting speech.) Even in the US, you have a right to voting in a way that's protected from others' observation.
Or, to put it another way: if you want to hold a political opinion, and then express it by voting, but otherwise keep it completely secret from your community... that's your right.
Private conversations are protected. So even in Germany if a report to me confides he admires Hitler I can't fire him for that. If he says so on a public channel, that is different (and depending on what is said might be criminal, but that is a time/manner/place restriction).
But the goal is to hold private political discussions as much as possible above economic retaliation.
Or, to put it another way: if you want to hold a political opinion, and then express it by voting, but otherwise keep it completely secret from your community... that's your right.