“If experience demands a presumption that a judge will seize every opportunity presented to him in the course of his official conduct to line his pockets, no canon of ethics or statute regarding disqualification can save our judicial system.” —Justice William Rehnquist1
A judiciary without honesty has little chance of executing its moral and constitutional duties, no matter how many rules of ethics exist. This is especially true in the United States, where the judiciary is afforded wide discretion. Facts and law require interpretation; justice and equity require judgment. Every decision to grant a motion, to follow precedent, to interpret a statute or facts, to set a sentence or damages—every decision left up to the discretion of a judge—is a potential opportunity for corruption.
Interesting article. It does discuss the Kids for Cash program in Pennsylvania.