Why Is It Such A Big Deal To Ask Someone Who They’re Voting For?

Who are you voting for? Seems like whenever you ask this question to someone, they get offended and act like your violating some sort of code. Whats the big deal? Why does it have to be such a secret? You ask me, I'll tell you without hesitation. Are people afraid of reaction? Or are they embarrassed by their choice?

All those people who carry political signs aren't worried about people knowing who they are going to vote for.