The Trump administration has taken steps and made claims that clash with legal opinions issued by a traditionally powerful agency that is part of the Justice Department, the Office of Legal Counsel.

The office has typically had an influential role in shaping internal government legal deliberations, and its court-like opinions are supposed to bind the executive branch unless the attorney general or the president overrides them or the office itself revokes them.

The disregard for its precedents is part of a broader pattern in which the clout and influence of the agency have eroded in the opening months of the administration.

Here are some examples that show that disconnect.

Spending

What the Trump administration has done

The Trump administration has frozen large amounts of spending authorized by Congress. It has justified those blocks with shifting legal rationales in court. But both President Trump and his White House budget chief, Russell T. Vought, have said that they believe the president has constitutional authority to refuse to spend taxpayer money that Congress appropriated for things the president does not like. That tactic is called impoundment, and Mr. Trump and Mr. Vought have said that they intend to re-establish that power despite a 1974 law that largely banned it.

What the Office of Legal Counsel has said

An opinion from 1969, written by William H. Rehnquist before he became chief justice, says the “existence of such a broad power is supported by neither reason nor precedent.” The office reinforced that conclusion in a 1988 opinion that says “the weight of authority is against such a broad power in the face of an express congressional directive to spend.”

Birthright Citizenship

What the Trump administration has done

Mr. Trump signed an executive order declaring that babies born on domestic soil to undocumented parents are no longer eligible for birthright citizenship and instructing government agencies not to issue them citizenship-affirming documents like Social Security cards.