In the case of Enochs v. Williams Packing & Navigation Co., Inc., the U.S. Supreme Court ruled in 1961 that federal courts cannot interfere with ongoing tax collections by the Internal Revenue Service (IRS) unless it is clear that under no circumstances could the government ultimately prevail and where equity jurisdiction otherwise exists. The case arose when Williams Packing, a Mississippi seafood company, sued to prevent IRS from collecting social security and unemployment taxes on payments made to commercial fishermen who caught fish for them. They argued these individuals were independent contractors not employees, hence exempted from such taxes. However, relying on what has come to be known as "the Anti-Injunction Act," which generally prohibits lawsuits restraining tax collection, the court held in favor of IRS stating there was no basis upon which it could be concluded that under no circumstance could they prevail.

In the dissenting opinion for Enochs v. Williams Packing & Navigation Co., Inc., Justice Black disagreed with the majority's interpretation of Section 7421(a) of the Internal Revenue Code, which prohibits suits to restrain tax collection. He argued that this section should be read as an absolute bar to such suits unless Congress has explicitly provided otherwise. According to him, a taxpayer who believes they are being subjected to unlawful taxation should pay first and then sue for a refund later in order not to disrupt government revenue flow. The majority’s decision allowing courts discretion in determining whether there is no reasonable basis for tax assessment could lead taxpayers into lengthy litigation over what constitutes "reasonable basis", thus potentially disrupting government operations by delaying tax collections.