If Senator Mike Duffy's defence is correct — and he may well be — then almost anything goes in Canada's farce of an upper chamber.

Fly around to party fundraisers on the taxpayer's dime? No problem. Pay your pals for "advice" on stuff they know little about? All within the rules. Bill for living expenses when you're at home? Why not?

After all, the Senate makes its own rules and they are written for senators, by senators.

Of course, Canadians' dislike of the Senate predates l'affaire Duffy. That it really is an undemocratic farce — although long past being amusing — is old news. For a vast, modern democracy to be saddled with an unelected upper house is an embarrassment not mitigated by the difficulty of changing it.

Instead, the Senate's ludicrously lop-sided makeup makes it doubly farcical. Duffy's tiny province of Prince Edward Island, for example, has four Senate seats for what is really the population of a small city — one senator for every 36,570 islanders.

But British Columbia has one senator for every 780,000 residents — six seats for more than 4.6 million people. So each Prince Edward Islander gets 21 times — 21 times! — more representation in the Senate than each British Columbian.

It's as though we dug up a relic of an ancient civilization. The four Atlantic provinces together have only 6.6 per cent of Canada's population, but 30 seats in the Senate — while Ontario gets just 24 seats for 38.5 per cent of the population. Could the rites of the pharaohs be any more bizarre?

But these absurd imbalances, fossilized by history and by the constitutional amending formula, are familiar. You can't say the same for the elastic rules which govern the Senate and which are now being cruelly laid bare at the Duffy trial.

Living with SARS

The Senate Administration Rules, the court has heard, are known as the SARS. Yes, that's also the name of a frightening disease. But that's probably a coincidence.

It turns out that it's the SARS which enabled — and even encouraged — the $65,000 in "consulting" contracts given by the Senate, at Duffy's request, to his buddy, Gerry Donohue. The actual value of Donohue's toil is mysterious; the RCMP alleges he did "little or no apparent work."

He supposedly helped Duffy with website design, for example. Asked if he knew anything about website design, Donohue testified, "no."

Gerald Donohue, seen testifying via video link in this court sketch, received thousands of dollars from Mike Duffy for work that ranged from research to advice on website design to handling payments for speechwriters and other contractors. (Greg Banning)

But never mind. The Senate bureaucracy approved and paid for the contract anyway — and why not? Senators wrote the rules and gave themselves complete freedom, within an office budget of $150,000 per year for each member, to hire consultants to do whatever. They could help, for example, with doing research and writing speeches.

To be tactful, let's skip over the assumption that senators are far too busy to do their own research or write their own speeches — even those who spent decades writing and speaking for a living. Like Mike Duffy.

Instead, let's consider the point made by Duffy's meticulous lawyer, Donald Bayne, who stressed every word as he read to the court from the SARS.Those rules say that, so long as it's within the budget, every senator is "entitled to full discretion over and control of the work performed on the senator's behalf" by staff or by contractors.

The rules further state that such employees and consultants shall be "hired at the direction of the senator, exercised at the sole discretion of the senator." So there's no way around it: the Senator has "sole discretion" and "full control" over the work to be done and the people who do it.

Hello, Gerry Donohue.

Party animals

Donohue, it turns out, wrote cheques to Duffy's fitness trainer. He also paid speechwriters like L. Ian MacDonald and Ezra Levant.

In MacDonald's case, the price was $7,000 — a bargain, by Duffy's account. The speech described why Duffy was a Conservative. Apparently, Duffy himself could not be expected to know that. Or to write about it himself. Or even to write the cheque himself.

In Ezra Levant's case, the popular firebrand's paid speech was about free speech — although Duffy says, "I had to tone it down a bit." Quelle surprise. But here's the point: the rules allowed all this and the Senate administration happily shelled out the cash.

And if you don't think it was worth the money? Or you don't think taxpayers should be on the hook? Well, that's adorable but, sorry, the Senate gives the senator "full discretion."

Mike Duffy and his lawyer Donald Bayne arrive for the fourth day of Duffy's testimony 0:59

But what about purely partisan events like fundraisers? Surely you can't charge taxpayers for those?

Oh, please. Take another trip to the SARS. The Senate Administration Rules make it clear that partisan events are totally kosher.

In fact, "partisan activities are an inherent and essential part of the parliamentary functions of a senator," the rules say, save only when there's an election or a nomination race going on.

So flying in a popular act like Duffy to fill the party coffers is evidently the taxpayer's job. Cynics who thought the Senate was designed to put party bagmen on the public payroll and to jet them around at public expense were right. Fundraisers, like contractors, are all within the rules.

Home is where the expenses are

But, come on. Dinging the taxpayer for living expenses when you're at your own home — that can't be right, can it?

Donald Bayne, Duffy's lawyer, read out the Senate's rules in court this week: "every senator is 'entitled to full discretion over and control of the work performed on the senator's behalf.'" (Justin Tang/Canadian Press)

Ah, for the days when we all thought that. We've learned otherwise, of course, because the Senate did pay Duffy's claims from the moment he took office — after living in Ottawa for 40 years. Or did the Senate staff think Duffy was commuting home to P.E.I. every night after his TV show in Ottawa?

On this point, Duffy seemed a lot more concerned than the staff — at first. He saw that the rules required senators to have a "primary residence" in the province they represent — which he did not. He had a cottage on P.E.I., but it needed a lot of work.

No worries! The Senate's legal advisors swiftly reassured him the rules did not define what "primary" means.

So, to ensure his constitutional eligibility to take his seat, he could just "declare" P.E.I. to be his primary residence, even if he lived in Ottawa "99 per cent of the time."

Presto! That was the official, written opinion of the Senate's non-partisan legal authorities. But, as magical as it seems, it gets more so.

The other question is whether such sorcery can sanctify a claim for living expenses at one's "secondary" home in Ottawa — meaning, the one you actually live in.

By now, you can see the answer coming: why, yes! It does! In fact, if you don't make such a claim, you undermine other senators who do and — too horrible to contemplate — you also undermine your own eligibility to sit in the Senate.

The guru speaks

For certainty, Duffy testified, he consulted Senator David Tkachuk, then the Conservative whip in the Senate and the party's guru on the knotty topic of the SARS. Duffy says Tkachuk insisted he should make the claims.

Could that be true? Tkachuk helpfully confirmed that he would say the same to any senator who asked.

"I would have told them," Tkachuk told the CBC, "that, if you 're staying here in Ottawa, that you should be claiming expenses because your primary residency is in your own province. So you want to make sure that's very clear that it is in your home province, because that's where you were appointed from and you jeopardize a Senate seat by not living there."

Ah. So you must claim the expenses so as not to endanger your right to claim the expenses. Gentle taxpayers — your Senate at work.

Of course, we don't yet know if the judge sees the elasticity of the rules as Mike Duffy does. Besides that, the senator has yet to address the infamous $90,000 cheque, which, he alleges, he was forced to accept by the PMO's "kids in short pants."

But we do know that the SARS say what they say. And, if Duffy's defence is right, the scandal lies not in what's illegal, but what's legal.