WASHINGTON >> In his first term, President Donald Trump seemed to relish ripping through the norms and standards of self-restraint that his predecessors had respected. Three weeks into his second term, hand-wringing about norms seems quaint.

Other presidents have occasionally ignored or claimed a right to bypass particular statutes. But Trump has opened the throttle on defying legal limits.

“We are well past euphemism about ‘pushing the limits,’ ‘stretching the envelope’ and the like,” said Peter M. Shane, who is a legal scholar in residence at New York University and the author of a casebook on separation-of-powers law. The array of legal constraints Trump has violated, Shane added, amounts to “programmatic sabotage and rampant lawlessness.”

Trump has effectively nullified laws, such as by ordering the Justice Department to refrain from enforcing a ban on the wildly popular app TikTok and by blocking migrants from invoking a statute allowing them to request asylum. He moved to effectively shutter a federal agency Congress created and tried to freeze congressionally approved spending, including most foreign aid. He summarily fired prosecutors, inspectors general and board members of independent agencies in defiance of legal rules against arbitrary removal.

More than two dozen lawsuits have been filed so far challenging moves by the Trump administration, though many overlap: At least nine, for example, concern his bid to change the constitutional understanding that babies born on U.S. soil to parents who are in the country illegally are citizens.

Courts have temporarily blocked that edict, along with his blanket freeze on disbursing $3 trillion in domestic grants from money Congress appropriated. And a federal judge has temporarily blocked the transfer of a transgender federal inmate to a male prison, pausing a move in line with one of Trump’s executive orders.

But those obstacles have been rare in Trump’s blitzkrieg, which has raised the question of whether, in his return to office, he and his advisers feel constrained by the rule of law.

This week, Trump moved to effectively dismantle the U.S. Agency for International Development and fold its functions into the State Department, making Secretary of State Marco Rubio its acting director. He had already crippled USAID by imposing a “temporary” freeze on disbursing foreign aid that Congress appropriated, which as time passes is increasingly at odds with the Impoundment Control Act of 1974.

Since the first Congress, it has been the legislative branch — not the president — that decides how to structure the executive branch, creating departments and agencies, giving them functions and providing them with funds to carry out those missions. And Congress has enacted laws that say USAID is to exist as an “independent establishment,” not as part of any executive department.

No matter. On Monday, Trump was asked whether he needed an act of Congress to do away with the agency. He dismissed that suggestion and insulted the officials who work there.

Trump and his appointees have also been firing people in naked defiance of statutes Congress enacted to protect against the arbitrary removal of certain officials, like civil servants or board members at independent agencies.

For example, Trump shut down three agencies by ousting Democratic members before their terms had ended. That effectively hobbled the agencies, the National Labor Relations Board, the Equal Employment Opportunity Commission and the Privacy and Civil Liberties Oversight Board, because they were left with too few officials for a quorum.

Congress created those agencies to be independent of the White House, and all three have been understood to have forms of protections limiting the president’s ability to remove their leaders without a good cause, like misconduct, although only the labor board statute says that. Regardless, Trump flouted the limit.

In so doing, the Trump administration appears to be setting up test cases should those officials sue, that would give the Republican-appointed supermajority on the Supreme Court an opportunity to expand on the so-called unitary executive theory. That doctrine, developed by the Reagan administration legal team, holds that the Constitution should be interpreted to prohibit Congress from enacting laws that limit a president’s absolute control of the executive branch.

Peter L. Strauss, a professor emeritus of law at Columbia University, said the Trump administration has embraced lawlessness.

“President Trump and his friends are ignoring both federal law and the, to me, clear limitation of presidential power in Article II of the Constitution,” he said. “The Constitution did not imagine what we are seeing. All one has to do is to read the whole of Article II to understand that.”

Even before taking office, Trump challenged the rule of law by declaring he would nullify a statute barring TikTok from operating in the United States unless its Chinese owners sold it.

He made the assertion even though the Supreme Court unanimously upheld the law.