If you go door-to-door campaigning, or if you have people going door-to-door for you, it’s probably not a good idea to wear mirrored sunglasses.
You may be knocking on doors in an area that is safe for your candidate, simply reminding people to get out and vote on election day, but even if those people agree with (most) of your positions, there’s a chance they’ll be distracted and put a little bit off-balance by the fact that you aren’t looking them in the eye and telling them exactly what you (or your candidate) stand for.
And if the people you are talking to disagree with you, you’re going to look downright shady–confirming every paranoid and ridiculous opinion they’d formed about you.
Politics isn’t a poker game. In politics, it’s reasonable for people to expect you to look them in the eye and lie instead of hiding behind mirrored glasses.