In the case of Harris v. Commissioner of Internal Revenue (1950), the Supreme Court was asked to determine whether a taxpayer could deduct from his gross income, for federal income tax purposes, amounts paid as alimony under a divorce decree. The petitioner, Mr. Harris had been making payments to his ex-wife and claimed these as deductions on his tax returns. However, the Commissioner of Internal Revenue disallowed these deductions arguing that they were not made because of any legal obligation arising out of marital or familial relationship but rather due to property settlement between two parties. The Supreme Court ruled in favor of Mr. Harris stating that such payments are deductible if they are made in discharge of an obligation imposed by law upon grounds akin to those which give rise to an obligation for alimony or support recognized by our domestic relations law; and it is immaterial whether this duty is enforced by threat against person or property so long as its performance will satisfy some part at least - however small -  of a legal liability arising out from family relationships.

In the dissenting opinion for Harris v. Commissioner of Internal Revenue, Justice Jackson disagreed with the majority's interpretation of tax law regarding alimony payments. He argued that under the relevant statute, a taxpayer should be allowed to deduct alimony payments from his income only if those payments are made as part of a legal obligation due to divorce or separation. In this case, Mr. Harris had agreed in an informal agreement with his ex-wife to continue making support payments after their legal obligation ended; however, he deducted these voluntary payments from his taxable income anyway. The majority held that because these additional support payments were made out of "a moral and honorable sense of duty," they could still be considered deductible alimony under tax law even though there was no longer any legal requirement for them. Justice Jackson contended that this interpretation stretched the meaning and intent of Congress when it passed legislation allowing deductions for legally obligated spousal support following marital dissolution but not voluntary post-divorce contributions based on personal feelings or morality.