I'd rarely agree with Brendan O'Neill about very much, but this article a while ago deserves a revisit.
“New Labour has discovered that transparency begets, not trust, but further suspicion – the more politicians make their personal purity into their major selling point, and the more they imply that parliament is a potentially corrupt and sleazy place, the more they invite scrutiny of their every foible and Kit Kat purchase.”There's capital-P-Politics to this as well. As I mentioned the other day, the word 'Candidate' comes from the latin Candidatus - derived in turn from the white robes that Senators wore to signify their purity of mind.
It also said 'look at me, I have the wealth and slaves needed to sustain a huge length of clean white linen every day.'
The modern day equivalent? The politician with the wind turbine on his house. Brand management is not a trivial or cheap business. If you only want people who can afford this - people with Richard Branson-type virtues - then the politics of personality will speed this process along.