In law, nonacquiescence is the intentional failure by one branch of the government to comply with the decision of another to some degree.
The issue of nonacquiescence first came to national prominence at the beginning of the American Civil War, in the famous case of Ex parte Merryman (1861).
Merryman involved the executive branch's refusal to comply with a U.S. circuit court decision that President Abraham Lincoln's suspension of the writ of habeas corpus was invalid.
[1] In the United States, federal agencies might practice nonacquiescence by refusing to accept the validity of unfavorable court decisions as binding precedent.
[2][3][4] Exceptionally, the Social Security Administration[5] and the Internal Revenue Service openly declare such conduct.