The rules were set Tuesday for the impeachment trial of the chief justice of the New Hampshire Supreme Court. Justice David Brock aces judgment by the state Senate Sept. 12 on four charges; the standard of proof will be up to each senator’s conscience; it will take a two-thirds majority to convict him.

That’s the easy part. How New Hampshire came to this crisis – Justice Stephen Thayer already has resigned, Justice Brock may be forcibly removed from office, faith in the state’s entire judicial system has been shattered – is baffling; a simple, mundane matter turned complicated and bizarre.

For the record, Justice Brock is charged with making an improper call to a lower court judge 13 years ago, with soliciting comments from then-Justice Thayer on a matter concerning Thayer’s own divorce case, with letting other justices comment on cases from which they were disqualified for conflicts of interest and, once an investigation began, for lying to investigators.

The simple explanation – other than the lying to investigators part – is that Thayer and Brock got caught in what some in New Hampshire describe as the “good old boy network.” The state judiciary, like the judiciaries in many states, is a close-knit community of old colleagues and law-school classmates; creeping laxity in maintaining proper distance finally caught up with the two justices.

But of course it’s not simple. The divorce of Stephen and Judith was a messy affair. After the former state Board of Education chairwoman alleged that her estranged husband illegally failed to report a $10,000 loan from a lawyer, she suddenly found herself unable to secure any legal counsel for the divorce proceedings and it got really messy. The state attorney general investigated and found Thayer tried to influence which judges would hear his divorce case and that Brock, at the very least, lent a sympathetic ear.

It’s not even that simple. All the judicial coziness that now so alarms New Hampshire lawmakers has been well known for years. It seems, in fact, to have become unconscionably offensive only after the state Supreme Court, Brock and Thayer on board, decided in 1997 that the method by which New Hampshire funds its public schools – local ability to pay – is unconstitutional. The state constitution says all children in New Hampshire are entitled to an “adequate” education. In the now infamous Claremont case, the court ruled that “adequate” means the same thing in poor Claremont as it does in wealthy Rye. The funding mechanism had to change.

Want complicated? Changing funding mechanisms to ensure adequate equity would require New Hampshire to adopt some type of statewide tax – sales, income, whatever. Problem is that no one has been elected to any office of stature in New Hampshire for 30 years without taking The Pledge, a solemn vow written and enforced by William Loeb, the late publisher on the Manchester Union-Leader, that New Hampshire will never have a statewide tax. From the governor’s office to the House and Senate chambers there’s been a lot of disagreement on how to solve the funding problem and a lot of agreement that it wouldn’t be a problem if Brock, Thayer and all those other justices hadn’t made it one. An early proposed solution, one that still has adherents, was, in fact, to impeach the entire state supreme court.

How about a touch of bizarre? There’s a Nixon involved. And a tape. David Nixon, one of the state’s most prominent lawyers, was Judith Thayer’s divorce attorney, suddenly he wasn’t. There’s an allegation that he was an intermediary in a plan by Gov. Jean Shaheen to get Brock to resign with a comfy golden parachute and immunity from prosecution. The governor says there was no such plan. Nixon says if there was, he had nothing to do with it. Brock’s lawyer says they have a tape – from the judge’s answering machine – in which Nixon alludes to the governor’s desire to be rid of him and offers to help any way he can.

New Hampshirites fed up with the whole ugly mess can take some measure of comfort, though. The widely circulated photo accompanying the news story Tuesday on ground rules for the Brock trial shows New Hampshire senators crowding around the familiar figure of Sen. George Mitchell. The stable, conscientious son of Maine who helped bring peace to Northern Ireland will be advising the senators during their proceedings. His diplomatic powers will be fully tested.