Many of us would view the ethics criteria from a zero tolerance perspective
Zero tolerance can be problematic. Sometimes it means applying punishment or expulsion at the slightest hint that their could be a problem, even when there isn't any actual problem, or it can lead to applying harsh punishment when there is only the most minor, technical, inadvertent violation. And there are a lot of issues related to corruption that aren't easy to deal with as a matter of law. In a sense delivering bills for a special interest that can bring out votes for a politician is corruption, at least if the politician is making the vote in order to get support from the special interest, rather than voting for what he sees as morally correct, or practically beneficial to the wider population, but its hard to prove why someone made a vote. As for the special interest itself being considered corrupt, well campaigning for your ideas and interests is the essence of democracy. If there is a direct bribe then you clearly have actionable corruption, campaign finance is less clear, and endorsing or otherwise getting out votes for a candidate still less clear.
When the ethical violation is clear and severe, I can see having no tolerance for it. When it is also a matter of law I can see prosecution. But many situations don't fit that criteria, partially (but not totally) because politicians will know how to work a system without clearly violating it. |