Sometimes it’s bad to be too good. After decades of honest government peopled with principled members of both parties, Maine finds itself ranked near the bottom when it comes to tough ethics rules.

States that have a culture of political corruption often have the strongest protections in their laws because they needed them. For instance, many states would have ended pension payments to someone like former Maine Turnpike Authority Director Paul Violette, who was sent to prison for helping himself to public funds, but Maine had so little experience with that kind of crime, it had no law on the books to respond to it.

Maine should not wait for the next scandal to start protecting itself from too-cozy relations between people in and outside of government. Everyone would benefit from some basic rules about mixing public service with private employment.

As reported last week by the Maine Center for Public Interest Reporting, someone can regulate an industry one day and then get a job working for a company in that industry the next. A regulator angling for a private-sector job might not be motivated to follow the strictest interpretation of the rules. No bribe needs to change hands to create an ethical problem.

Several bills before the Legislature this year would stop such a move, requiring a period as long as five years between moving from an executive branch agency to a business in the same industry.

This is important not only to prevent the thankfully rare instance of a public official misusing his office for personal gain, but also to give credibility to government agencies. Decisions by regulators are less likely to be seen as improper by the people who end up on the losing end of them.

It’s not enough to say that Maine is a small state and people of quality are bound to move from job to job. That may be true, but the state is big enough to shut the revolving door between government, industry and lobbying.

Maine has been lucky to avoid the kind of corruption that plagues other states, diverting public resources and destroying confidence in government agencies. Once that trust has been breached, it is hard to restore it. The Legislature should take action and protect Maine from this potential weakness.