Attorney General William Schneider issued a letter last week that clearly spelled what state Treasurer Bruce Poliquin should not do if he wants to avoid violating the Maine Constitution.

Schneider said Poliquin should not actively manage his real estate investments and he should not go before any governmental body on behalf of entities that he owns.

What Schneider doesn’t address is the fact that Poliquin already has done those things while he was serving as treasurer.

It’s fine to say that Poliquin should not do them any more, but it still leaves the question of what should be done about his past activities.

This is the question that state Rep. Mark Dion, D-Portland, is asking, and rightly so. Dion, a former Cumberland County sheriff, knows that there are few opportunities for do-overs in law enforcement, and judges are rarely impressed with an I’ll-never-do-it-again defense.

In December, Poliquin went before the Phippsburg Planning Board to expand operations at a beach club near a residential development he built. Poliquin now admits that was a mistake, telling a Portland radio station, “That was a dumb thing to do.”

It was also an easy thing to avoid.

The Constitution prohibits the treasurer from engaging in commerce when he is in office. Other treasurers have interpreted that as a mandate to sell a closely held business, or resign from a law partnership.

Poliquin could have gotten legal guidance about how to proceed before he took the oath of office, but he chose not to.

Lawmakers should not give him a do-over. Poliquin’s case should be pursued either in a legislative arena or in court.

And if Poliquin has been found to have violated the Constitution, he should do the right thing and step down.