Judicial deference to administrative agencies is often viewed as a dichotomous choice between full deference and no deference, ignoring considerations of institutional and political context. I argue that a court's decision on whether to defer to an administrative agency is more complex and is conditional on the political salience of the substantive issue in the case. I test this theory in the context of the U.S. Courts of Appeals using a sample of cases decided between 1961 and 2002. The results show that when dealing with non-salient cases, the level of deference to agencies is static, but in salient cases the level of deference is strongly related to the ideological congruence between the court and the agency.Every legal power must have legal limits, otherwise there is dictatorship. In particular, it is a stringent requirement that a discretion should be exercised for a proper purpose, and that it should not be exercised unreasonably. In other words, every discretion cannot be free from legal restraint; where it is wrongly exercised, it becomes the duty of the courts to intervene. The courts are the only defense [sic] of the liberty of the subject against departmental aggression. In these days when government departments and public authorities have such great powers and influence, this is a most important safeguard for the ordinary citizen: so that the courts can see that these great powers and influence are exercised in accordance with law. 1 We accord deference to agencies . . . because of a presumption that Congress, when it left ambiguity in a statute meant for implementation by an agency, understood that the ambiguity would be resolved, first and foremost, by the agency, and desired the agency (rather than the courts) to possess whatever degree of discretion the ambiguity allows. 2 1 Raja Azlan Shah Ag. CJ writing for the Federal Court of Kuala Lumpur [Malaysia] in Pengarah Tanah dan Galian,