Rising conservative star and now-governor of Louisiana seems to be on the side of the angels with this successful ethics reform package that should clean up some of the bayou muck off the state's legendarily shady politics.
It does seem to me, though, that the condition of a jurisdiction's formal policies on government ethics are more likely to be a symptom than a cause of the actual state of play. If you have the relevant social conditions to support good government -- competent media, engaged citizenry, civil society groups that can form the basis of electoral coalitions, a political culture that values honesty -- then a politician who engages in a lot of shady behavior is likely to find himself voted out of office whether or not the shadiness in question is formally illegal. Conversely, absent adequate social conditions even the most admirable legal framework becomes a dead letter -- nobody investigates violations and/or nobody cares. At the end of the day there are always going to be loopholes in whatever scheme you create. You see good government when and where the citizens want it and are able to punish those who don't give it to them.