Well it's nearly unanimous. The candidate who willingly voices even unnecessarily unpopular opinions is the more open and almost certainly the more honest candidate. The less forthcoming candidate with a carefully manicured public image who never once voices an opinion unpopular in the community, even if they share a couple unpopular nationally, is the less trustworthy one. One of these in our town turned out to be bankrolled by a local wealthy monopolist, sometimes they're after their own power and popularity or have another hidden agenda, but it's not going to be good. Unfortunately, it does work a lot, maybe even most of the time. But it's worth knowing the pattern.
And there is no greater threat than a honest candidate to these people. An honest member of the board or whatever might point out things that are very inconvenient. They absolutely must be crushed.