Suppose credible allegations of a violent crime were levelled against a public figure. Then, as police were investigating, another allegation, equally credible, was brought forward as well. And then, while those were being checked out, yet another accusation popped up -- this one more sensational still, but also more questionable.

Would we keep investigating the earlier allegations, along with the latest one, maintaining a presumption of innocence until at least one of them was proven? Or would we finally decide that the cumulative weight of all the allegations amounted to a conviction, without any of them ever going to trial?

As long as we maintain some semblance of a fair judicial system, it would be the former. So why not the same basic standard in politics?

Judy Sgro probably shouldn't be treated as a martyr. It's entirely possible that she - or at least members of her staff - did more than enough to justify her removal from Cabinet. But the manner of her ouster (sorry, resignation) set a troubling standard for what qualifies as a firing offence.

If Ms. Sgro had temporarily stepped down with a reasonable expectation that she might return, it would be different. There is a strong case to be made that the ethical cloud over her head made it impossible for her to perform ably as a senior minister. But Paul Martin's flattery notwithstanding, this is not being treated as a temporary departure pending the outcome of investigations so much as a damning end to her Cabinet career.

The condemnations have come from all sides. "It took week after week, month after month of revelation until the minister herself finally resigned and in the meantime, now we've got a big mess to clean up," Conservative leader Stephen Harper said in blaming Mr. Martin for not punting her sooner. On the other end of the political spectrum, the Toronto Star proclaimed there must be "zero tolerance for ministerial scandals" and identified Ms. Sgro as "the first political casualty" in Mr. Martin's government.

Through it all, the obvious question goes unanswered. What, specifically, did Ms. Sgro do to lose her job?

Was it affording preferential treatment to the now-infamous Romanian stripper who reportedly volunteered on her campaign? Covering up a campaign donation from a Pakistani businessman? Accepting pizza and garlic bread in return for a promise to help someone ordered deported stay in the country?

Clearly, it was not one of those on its own. She wasn't fired after the first allegation, nor the second one. And although it immediately preceded her departure, it couldn't possibly have been the final one -- not when it was by far the shakiest of the three, given what we've since learned about her accuser.

None of the allegations should amount to anything until they're proven. And while the chances seem slim, there's no reason to exclude the possibility that Ms. Sgro is the victim of three separate misrepresentations or misunderstandings. So what her ignominious fate tells us is that 0+0+0 could conceivably equal 1.

That sets a disturbing precedent. Whether or not Ms. Sgro was victimized by this brand of arithmetic, it'll happen to some other unfortunate soul sooner or later. After all, the lesson to bloody-minded political operatives is a simple one: Forget about hunting for one legitimate, fleshed-out scandal to bury a foe. Just keep the allegations rolling, and sooner or later, their cumulative weight will do the trick.

This isn't about Ms. Sgro -- an unremarkable political talent whose departmental stewardship was raising behind-the-scenes questions even before strippers and pizzas hit the headlines. It's about establishing some sort of fair standard to ensure politicians can avoid having their reputations permanently blackened without some evidence of wrongdoing.

Determining guilt and appropriate punishment in the political sense is not as black-and-white as in the criminal justice system. Optics and expectations and personal relationships all conspire to make it a good deal more subjective. But the least we can do is carefully examine the evidence before cheering politicians' public hangings.