Well my reply to the second part is already in my post: "harsher treatment of lying politicians, for it to be the norm that a really big lie forces a resignation or period of apology and social "probation" enforced by the voting public. We should value the truth more than we do." That especially covers the big lies like fraudulent statistics. Still leaves room for the more subtle, misleading lies, but deception is something that is never going away.
It's on us because politics is choices about values, and our values are reflected pretty accurately in most areas, with wealth distribution being the biggest exception, and maintaining that biggest of lies requires gargantuan effort. We like lying scumbags who pander to our base emotional needs, and most people I see protesting that are at best a pack of much-protesting Lady Macbeths . I also don't think politicians are, at a baseline irrespective of today's Republicans (who go much further than merely pandering to our base emotional needs), quite as dishonest as we think they are. I'm a notch to the skeptical side of the JVS view (that they are significantly more honest than us), because branding is fundamentally dishonest and politicians are euphemizing and branding constantly, and can't help but be somewhat dishonest all the time because of that.
I think it's still fundamentally impossible to be sufficiently honest on a personal level, as a political representative, and be effective. Even figuring out when to act as a trustee and when to act as a delegate can put you into impossible corners where identifying the morally right thing is difficult and somebody is getting fucked no matter what you decide. I don't think people are good at thinking about those sorts of dynamics, because most people aren't very intelligent. The best they can do is default to cynicism so they won't feel fooled.