President Joe Biden is putting handguns in the spotlight following the shooting at Robb Elementary School in Uvalde, Texas. “A 9 mm bullet blows the lung out of the body," Biden claimed. "So, the idea of these high-caliber weapons — there’s simply no rational basis for it in terms of self-protection, hunting."

This is not the first time Biden has taken a stance against 9 mm handguns. “Why should we allow people to have military-style weapons, including pistols with 9 mm bullets and can hold 10 or more rounds,” Biden said at a campaign fundraiser in 2019. Fact-checkers rushed to provide cover for then-candidate Biden and accused the NRA of misconstruing the statement in an article the organization published. “His statement here, as he has often said, is about banning high-capacity magazines for use in any type of weapon,” a Biden campaign spokesman told Politifact.

When Biden says there is “no rational basis” for 9 mm bullets, it's clear his stance is not limited to magazine restrictions. Any legislation targeting pistols that utilize 9 mm rounds will affect millions of people. Handguns using 9 mm ammunition are the most commonly produced model in the United States. About 58% of pistols produced in 2020 utilize 9 mm rounds, according to the ATF’s Annual Firearms Manufacturing and Exportation Report.

Canadian Prime Minister Justin Trudeau, meanwhile, is pushing for sweeping gun control legislation while Biden targets America’s most common handguns. Trudeau announced new legislation on Monday that would halt all future handgun sales, transfers, and imports. “We need only look south of the border to know that if we do not take action, firmly and rapidly, it gets worse and worse and more difficult to counter,” he said. The law allows Canadians to possess a handgun if they currently own one but bans the transfer of these weapons to aspiring gun owners.

Democrats in America’s capital tried to ban handguns, but the Supreme Court struck down the law in District of Columbia v. Heller. “It is enough to note, as we have observed, that the American people have considered the handgun to be the quintessential self-defense weapon,” wrote Justice Antonin Scalia in the court’s opinion.

Trudeau’s actions may inspire American liberals to push for similar legislation. Compounded with Biden’s statement on handguns, it is clear that the slippery slope gun owners warn about is not a fallacy but a reality. A change in the national discourse of this magnitude should not be taken lightly.

The Supreme Court’s ruling in Heller protects handguns from egregious government regulations, but American gun owners should not become complacent. The conservative hold on the Supreme Court is not permanent. Hillary Clinton claimed the Supreme Court was “wrong” about gun rights while talking to campaign donors at a fundraising event in 2015. Precedents established by cases like Heller can easily be overturned under a liberal court.

Trudeau is capitalizing on the school shooting in Uvalde to justify his legislation. Some provisions in the proposal are related to the shooting, as the bill also includes magazine restrictions on rifles and establishes a national red flag law. The effectiveness of these proposals can, and should, be debated, as they are related to the issues at hand. The decision to include a handgun transaction ban in a proposal inspired by a rifle-related crime is the best example yet of what happens when you concede ground on gun rights.

Trudeau’s proposal during America’s national debate over gun control legislation proves the underlying truth of the slippery slope argument. Canadian citizens gave Trudeau an inch, and now, he’s taking a mile. Americans should pay attention to what is happening across the northern border. If Joe Biden has his way, the same thing will happen on our soil.

James Sweet is a summer 2022 Washington Examiner fellow.