It would be useful to take seriously the 600 or 800 people whose response to Wednesday’s melee in the House of Commons was to inquire how everyone would have reacted if Stephen Harper had been the offending prime minister.

Let us go through the exercise.

Say it’s May of 2012 and Harper, early-ish in his third mandate—the only one in which a majority of MPs were Conservatives—looks up from his seat to discover some silly business going on between the Liberal whip and a bunch of NDP MPs. The Conservatives’ chief government whip shrugs. Canada’s 22nd prime minister leaps up from his seat and marches double-time across the aisle.

Grabbing the Liberal by the elbow, Harper growls “Get the f–k out of the way” to the New Democrats, his elbow colliding with one. She misses the next vote to collect herself.

How do you suppose that’d have gone over?

Note that it takes effort to imagine all this, because in real life Harper never did any such thing. Sure, he used parliamentary rules to limit debate, ran up big budget deficits, and had staffers devoted more or less full-time to his hagiography. In other words, he did a lot of things Justin Trudeau has begun doing. But Harper never personally racked up a casualty list. (I exaggerate for comic effect. You are offended. Get in line.)

If he had, it is easy to suppose the Liberal garment-rending would have been thunderous, that Michael Harris would have two-thirds of his next book written by dawn, and that Conservatives, while not thrilled with their man’s comportment, would be impatient with their opponents’ inability to describe it without quavering voices.

In other words, where you stand on such things often depends on where you sit. Perhaps we can agree on this much: Harper didn’t do anything resembling what Trudeau did, because prime ministers shouldn’t act that way. In 21 years here I’ve never seen any prime minister grow so grandly weary with the Commons routine that he felt authorized to jump up and push his colleagues around. Trudeau’s tantrum was bad parliamentary procedure (the vote could have proceeded even if Gord Brown, the Conservative whip, had never found his seat, as Aaron Wherry pointed out). It was loutish language, if we stick to the principle that nobody should use words inside the House of Commons that just about everyone uses outside. It gave help to Brown that Brown hadn’t requested, and it hurt Ruth Ellen Brosseau in a way no MP should have to tolerate. Trudeau was right to apologize immediately after, then in greater detail and at length Thursday morning.

Trudeau’s hissy fit was the surprising consequence of a box the Liberals had built diligently for themselves. Their election platform amounted to a promise to defy physics. They would accomplish more than any government in a generation, while permitting debate on any subject to run as long as MPs wanted, while ending the Conservative practice of lumping unrelated topics together into a single bill. Infinite debate on an infinity of bills. It was only a matter of time before something gave. Either they would not be able to implement their agenda, or they would have to stop doing it politely.

The assisted-death bill, C-14, was the camel that broke the back of Trudeau’s straw house. OK, that’s a lousy mixed metaphor, but bear with me, it’s been a weird week. The bill takes Parliament into new and hotly contested moral terrain. It pushes hard up against a deadline set by the Supreme Court, thanks to Conservative dithering at the end of the Harper years and an overstuffed Liberal agenda since last fall. Trudeau was faced with a choice that he will have to face many more times as prime minister, between his agenda and decorum. Motion 6, a truly impressive scythe for cutting down opposition powers, was his response: He would rather get things done than be nice. Today, his already tenuous tactical position weakened by his own temper, he withdrew Motion 6. But the problem remains: Forced to be nice, he will now get less done.

Trudeau knew he had lost the day. He resisted the temptation to be grudging. He apologized repeatedly to just about everyone for just about everything he’d done on Wednesday. His opponents were, in the main, less self-aware. The parade of shocked expressions, the reference one MP made to “impact statements” as though MPs had witnessed a beheading, the interminable procession of theatrically wounded survivors, suggested it had not occurred to MPs that Canadians might be watching all of them, and judging them separately and as a species.

In particular, New Democrats who had lined up like cattle on the floor of the Commons to block a colleague—to the apparent grand satisfaction of the only major-party leader in the history of the country so odious as to lose a leadership-review vote outright—seemed unable to understand that buttering the bread of their grievance a yard thick might not be striking the entirely appropriate note.

So there is blame to go around. But none of it excuses Trudeau, whose assisted-dying bill, friendless and unlikely to last in court, joins his electoral-reform plan as evidence that the House of Commons is the part of his job he understands least, likes least, and can manage least.