Back in late 2005 and early 2006, when the Liberals were about to be booted from office for a decade by the Stephen Harper Conservatives, they ran a series of attack ads that tried to paint Mr. Harper as a vaguely fascistic politician with a penchant for radical American conservatism and a disdain for Canadian values.

The 30-second spots accused Mr. Harper of all sorts of unCanadian activity. One of them made the claim that his leadership campaign might have been funded by right-wing groups in the United States. “They have money, maybe they helped him. We just don’t know. He just won’t say," it said.

The worst of the lot, though, was the ad that accused Mr. Harper of planning, if elected, to send the army into Canadian cities. “Canadian cities. Soldiers with guns. In our cities. In Canada," the narrator intoned in punctuated salvoes, over an ominous background drone of kettle drums.

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Each of the ads ended with the party’s campaign slogan: “Choose your Canada.” And choose Canadians did. They gave Mr. Harper the first of two minority governments and then elected him to a majority in 2011. The ads were a bust, because Canadians saw them as manufactured nonsense.

Now, 13 years later, the Liberal Party is trying the same discredited messaging in order to stave off defeat in the general election in October.

Having formed a strong majority government in 2015, the Liberals today are neck and neck with the Conservatives in the polls. A broken promise about electoral reform and a scandal that saw two top ministers and a chief of staff resign will do that to a governing party.

But, while voters are showing signs of disillusionment with the Trudeau government after only one term, they are unfamiliar with Conservative Party Leader Andrew Scheer. Just like Mr. Harper was in the 2006 election campaign, Mr. Scheer is not even two years into his job as party leader. An unknown quantity, in other words.

And so the Liberals are up to their old tactics, trying to portray Mr. Scheer as a menace to Canadian values. Their recent hypocritical flip-flop on the issue of conversion therapy is a case in point.

Conversion therapy is the discredited practice of trying to convert LGBTQ people to heterosexuality. The World Health Organization, the Canadian Psychological Association, the American Psychiatric Association and the American Medical Association have all decried it.

In February, a federal NDP MP launched a petition calling on the House of Commons to ban conversion therapy for minors. It quickly picked up 18,000 signatures. But in March, the Trudeau government said that, while it opposed the practice, it wouldn’t take specific measures to ban it, on the grounds that it’s a provincial jurisdiction and that there are already Criminal Code offences to cover cases of kidnapping, forcible confinement or assault if someone were compelled to undergo the therapy against their will.

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It was a reasonable response, but it didn’t go down well with the LGBTQ community. So, in June, facing a backlash, the Liberal government let it be known that it was suddenly looking into Criminal Code reforms to “better prevent, punish, and deter this discredited and dangerous practice.”

What happened next? Mr. Scheer was asked by media if he supported the Liberals’ hypothetical reform. He responded that he and his party are “opposed to any type of practice that would forcibly attempt to change someone’s sexual orientation against their will,” but that he would wait to see any proposed reform before responding.

A perfectly reasonable answer, but within hours Mr. Scheer was being portrayed by Liberal MPs and spokespeople as having no interest in protecting LGBTQ people, and furthermore lacking empathy – for taking exactly the same position as their party.

It was a laughably sleazy attack. Were the Liberals to turn this into one of their 2006-style campaign ads, it would go something like this: “Does Andrew Scheer oppose conversion therapy? He says he does. But maybe he doesn’t. What’s he hiding?"

It didn’t work then, and it won’t work now. Federal elections in Canada, a country of centrist voters if there ever was one, are never about radical swings between left and right. A decade of Conservative rule did not turn Canada into Alabama North. There are good reasons to vote Liberal, or against the Conservatives, but this isn’t one. Don’t be fooled by outdated scare tactics.