In Davis v. United States (1973), the Supreme Court ruled on a case involving income tax deductions for expenses related to maintaining a home office. The petitioner, Jefferson Davis, was an employee of the Tennessee Valley Authority who worked from his home office and sought to deduct these expenses from his federal income taxes. The IRS denied this deduction, arguing that because he was an employee rather than self-employed, he could not claim such deductions under Section 162(a) of the Internal Revenue Code. Upon appeal by Davis, the Supreme Court upheld this decision in favor of the IRS with a unanimous vote. The court reasoned that while some business-related costs can be deducted if they are necessary and ordinary for conducting trade or business activities as per Section 162(a), it does not apply when one is working as an employee out of convenience rather than necessity imposed by employment conditions itself. This ruling set precedent limiting employees' ability to claim home-office expense deductions unless their employer specifically requires them to maintain such space for work purposes.

In the dissenting opinion for Davis v. United States, Justice Marshall argued that the majority's decision was a departure from established Fourth Amendment jurisprudence. He contended that by allowing police to search an individual without probable cause simply because they had been lawfully arrested, the court was undermining essential privacy rights protected by the Constitution. Furthermore, he disagreed with their interpretation of "incident to arrest" searches as being primarily concerned with officer safety and evidence preservation; instead, he believed these types of searches should be limited in scope and conducted only when there is reasonable suspicion that an individual may pose a danger or attempt to destroy evidence. In his view, this ruling gave too much discretion to arresting officers at the expense of personal liberties.