You remember chemistry class, don’t you? Of course you do.

In chemistry class, a “litmus test” was the way you checked the acidity of a substance. You remember: you’d dip a bit of pinkish litmus paper into some liquid and watch for the reaction.

“Acidic” is a probably good way to describe the way Donald Trump is treating Canada these days. In so doing, Trump and his administration have become a bit of a political litmus test of their own. Everyone in public life is now being measured by the way they deal with Trump’s “51st state” fantasy.

Just ask Keir Starmer, the socialist British Prime Minister who was in Washington, D.C. this week to pay obeisance to the newly-returned U.S. President. While there, he was asked twice about Trump’s attacks on Canada. Both times, Starmer revealed himself to be a Chamberlain-type coward. A shiftless, feckless, gutless wimp.

“You mention, Canada,” Starmer sniffed to reporters. “I think you’re trying to find a divide between us that doesn’t exist.”

So much for Commonwealth unity. Go to straight to Hell, Keir.

The week before it was Wayne Gretzky. Those of us who grew up as Calgary Flames fans always intensely disliked the former Edmonton Oiler, known locally as Whine Gripesky. But when Gretzky was insufficiently pro-Canada (which gave him everything) and a bit too pro-Trump (who didn’t), he swiftly became the target of Canada-wide animus. Bobby Orr even waded in to defend Gripesky – and now lots of Canadians are mad at Orr, too.

Elon Musk, with actual Saskatchewan antecedents and a Canadian citizenship: nearly 350,000 of us, at press time, have signed a petition to strip him of that citizenship.

King Charles, who has said precisely nothing about the territorial integrity of us, a member of the Commonwealth that still has his image burnished on our currency: total silence.

And on and on. Many, many former allies are being measured, in this Trumpian political litmus test, and many are being found wanting.

It works in reverse, too. Consider Doug Ford and Pierre Poilievre.

Both are plain-talking politicians. Both aren’t afraid of a scrap. Both lead Conservative parties. But only one of them has won a massive and historic third legislative majority this week – and the other one has blown a 30-point poll lead in a matter of weeks. Why?

Again, it’s the Trump litmus test.

Ford has shown us he is prepared to take the anti-tariffs fight to Trump, over and over. Poilievre, meanwhile, just hasn’t. He’s tried to avoid sounding too critical of Trump, and Canadians have noticed. They’re growing unhappy with the Conservative Leader, just like they’re unhappy with Gretzky, Orr, Starmer and the rest of the Vichy bunch.

Are Canadians delighted Justin Trudeau is gone next week? Damn straight they are. But are they in love with prime minister-to-be Mark Carney? No way. If voters like Carney, it’s because he is the polar opposite of Trump – he’s bland, he’s boring, and he’s a banker.

But the principal reason why several polls this week revealed a Carney-led Liberal Party to be in first place is this: Canadians suspect Poilievre is in the same category as Starmer, Gretzky and the rest. When the chips are down, they surmise, Poilievre will side with Trump.

I’ve been an advisor to a former Liberal Prime Minister (and, full disclosure, someone who has given communications advice to both of the governing parties at Queen’s Park over the years), and I don’t believe – not for a New York minute – that Poilievre admires Trump.

Poilievre is everything Trump isn’t – a policy wonk, a traditionalist, a disciplined politician.

But Poilievre’s persona and policies have clearly hurt him during applications of the Trump litmus test. His style of communications is too angry and too simplistic, too often – just like Trump.

His policies – lashing out at media, favouring slash-and-burn governance – sound too Trumpy, too. It’s hurting him, big time.

Poilievre needs to take a long, hard look at what has happened to Messrs. Gretzky, Orr, Musk et al.: Canadians used to be really proud of them. Now, we’re really, really mad at them.

Why? They’ve failed the Trump litmus test.

Poilievre is being measured, too, right now. He needs to make some big changes, fast.

If he doesn’t, he’ll fail the only test that matters – in an election that is just weeks away.