In the United States v. Davis et ux., 1969, the Supreme Court ruled on a case involving income tax deductions for educational expenses. The respondents, Mr. and Mrs. Davis, had claimed a deduction for tuition fees paid to send their children to racially segregated private schools after public schools in their area were desegregated by court order. The Internal Revenue Service (IRS) disallowed these deductions under Section 262 of the Internal Revenue Code which prohibits personal, living or family expenses from being deducted. The Davises argued that they sent their children to private school not out of personal preference but due to what they perceived as a breakdown in discipline and academic standards at desegregated public schools; thus making it an "ordinary and necessary" business expense related to Mr.Davis's profession as an attorney who needed his kids well-educated. However, the Supreme Court rejected this argument stating that even if such considerations could transform personal expenses into deductible ones - which was doubtful - there was no evidence showing that sending kids to segregated private school improved quality of education over attending integrated public school.

In the dissenting opinion for United States v. Davis et ux., Justice Douglas argued that the majority's decision was a departure from established precedent regarding tax law and constitutional rights. He contended that taxpayers should not be penalized for asserting their Fifth Amendment right against self-incrimination, as this would effectively nullify this crucial protection. Furthermore, he disagreed with the majority's interpretation of what constitutes "voluntary" disclosure under tax laws, arguing that it is unreasonable to expect taxpayers to forfeit their constitutional rights in order to avoid penalties or prosecution. In his view, such an expectation undermines both the spirit and letter of our Constitution’s protections.