No one has ever accused Donald Trump of being humble (well, except Donald Trump). Yet at times, the president takes actions pitched as flowing from a sense of constitutional humility — that however much he wants to do something, he just can’t.

His decision to rescind the Deferred Action for Childhood Arrivals program is one example. DACA was an administrative initiative that President Barack Obama’s Justice Department determined was legally permissible under the Immigration and Nationality Act (as was the much larger DAPA program Obama announced in 2014.)

Trump, by contrast, declared in September 2017 that “the program is unlawful and unconstitutional,” relying on a brief letter from Attorney General Jeff Sessions that abruptly reversed DOJ’s earlier reasoning. “President Obama bypassed Congress,” Trump lamented, thus “… violating the core tenets that sustain our Republic.”

Fast-forward to Friday, when Sessions announced a new Justice Department rule that would ban the use of “bump stocks,” an accessory that can be added to semiautomatic weapons to increase their rate of fire, mimicking machine guns. The use of bump stocks helped Stephen Paddock kill 58 people (and injure more than 500 others) in Las Vegas in October. The proposed new rule came just before the massive student-led March for Our Lives against gun violence, an event that drew hundreds of thousands of people to Washington on Saturday.

The private ownership of machine guns is generally illegal; bump stocks are not. But after the Las Vegas massacre and then again after 17 people were fatally shot at a high school in Florida in February, Trump supported the regulatory prohibition of bump stocks. He asked the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) to promulgate a new rule doing just that. “Bump stocks are going to be gone,” Trump said on March 8.

And on Friday, the president tweeted:

Note that the Obama administration had not “legalized” bump stocks. Instead, in 2013 it found that the National Firearms Act did not give the ATF the power it would need to classify them as illegal. Bump stocks “were not classified as machine guns,” ATF determined, because they were “unable to convert a weapon to shoot automatically.” Thus, “ATF does not have the authority to restrict their lawful possession, use, or transfer.”

Further, the Trump administration has itself confirmed that reading of the law. On April 6, 2017, the ATF’s Michael Curtis wrote that a bump stock submitted for review was “NOT a machinegun under the NFA.”

The newly drafted regulation, however, changes ATF’s interpretation of “automatic” and asserts that bump stocks allow a shooter to fire more than one round “by a single function of the trigger.”

Suddenly, then, these devices can be regulated under the NFA.

What the Trump administration is doing here — like the DACA rescission, and the cancellation of stabilization payments under the Affordable Care Act, and the use of the Antiquities Act to roll back national monuments rather than create them, and the use of “national security” provisions to impose steel tariffs — may or may not reflect the correct interpretation of existing statute. It will certainly be contested in court — where ATF’s past interpretations of the law will not help the administration’s case. It’s also unclear, given Trump’s “2 for 1” executive order last year, whether DOJ will have to come up with two other regulations to rescind, so that it can issue this one.

But one thing is clear. When it comes back to the question of “core tenets” and deference to Congress, the Trump administration is just as happy as its predecessors to interpret the law in whatever way allows it to implement the policies it prefers.