I find the statement creepy. Why do my neighbors need to know? Why should I "make sure" my neighbors know what I'm expected to believe they think I'm supposed to do?
I mean, it's sort of true that if one were for Donald Trump in my neighborhood, one wouldn't feel secure putting up a sign. So the absence of a sign could raise a inference that you might want to dispel by putting up a Hillary sign... even if you were for Donald Trump.
If only there were a "Hey, everybody, I never put up a sign" sign. But it might just prod people to think that's probably because you realize we'd have to hate you if we knew what you thought.
"And if my thought-dreams could be seen/They’d probably put my head in a guillotine" — Bob Dylan.