You might want to look at https://en.wikipedia.org/wiki/Secret_ballot https://en.wikipedia.org/wiki/Secret_ballot https://en.wikipedia.org/wiki/Preference_fal

You might want to look at https://en.wikipedia.org/wiki/Secret_ballot https://en.wikipedia.org/wiki/Secret_ballot https://en.wikipedia.org/wiki/Preference_falsification https://en.wikipedia.org/wiki/Preference_falsification https://en.wikipedia.org/wiki/Social-desirability_bias https://en.wikipedia.org/wiki/Social-desirability_bias (I think Brendan Eich's experience with suffering enormous professional consequences for having donated to the Proposition 8 campaign -- a fact which was public under California electoral laws -- is a concrete example. You could imagine the same kind of consequences for everyone who voted for the proposition, in which case many people would not only choose their political donations based on fear of public opinion and social and professional consequences, but would even choose their votes based on those same fears.) These issues might not convince you, but they represent a sample of other people's answers to your question. Also, in many places, depending a lot on the culture and history, a powerful local figure such as a large employer, union leader, "patron", or religious leader will actively try to tell people how to vote, if given the opportunity. https://en.wikipedia.org/wiki/Political_machine https://en.wikipedia.org/wiki/Political_machine https://en.wikipedia.org/wiki/Electoral_fraud#Vote_buying https://en.wikipedia.org/wiki/Electoral_fraud#Vote_buying https://en.wikipedia.org/wiki/Treating https://en.wikipedia.org/wiki/Treating https://en.wikipedia.org/wiki/Clientelism https://en.wikipedia.org/wiki/Clientelism