The Southeastern Express Company v. Robertson, State Revenue Agent case in 1923 revolved around the issue of whether a state could impose taxes on interstate commerce businesses. The Southeastern Express Company was an interstate carrier that also conducted business within Alabama and was taxed by the state for its intrastate operations. However, it argued that this tax violated the Commerce Clause of the U.S Constitution which prohibits states from taxing interstate commerce activities. The Supreme Court ruled against Southeastern Express Company stating that while states cannot interfere with or tax purely interstate commerce, they can levy taxes on companies conducting both intra- and inter-state business as long as those taxes are fairly apportioned to reflect only intrastate activity. This decision upheld Alabama's right to collect revenue from businesses operating within its borders even if they were involved in broader commercial activities beyond state lines.

In the dissenting opinion for Southeastern Express Company v. Robertson, State Revenue Agent, et al., Justice McReynolds disagreed with the majority's ruling that upheld a Mississippi tax on interstate commerce. He argued that this decision contradicted previous Supreme Court rulings which had established that states could not impose taxes on interstate commerce due to its federal nature under the Commerce Clause of the U.S. Constitution. According to him, allowing such state taxation would lead to an untenable situation where each state could levy their own separate taxes on interstate business activities thereby creating a chaotic and unmanageable system of taxation across different jurisdictions in contradiction with principles of uniformity and fairness in taxation policy as envisaged by framers of constitution.