Why would a state statute requiring a Mail Order Company to collect sales tax be unconstitutional?

The correct answer highlights the potential conflict between state laws and the Commerce Clause of the U.S. Constitution. The Commerce Clause grants Congress the power to regulate commerce among the states, which includes the prohibition against states imposing undue burdens on interstate commerce.

In this scenario, if a state statute requires a mail order company to collect sales tax, it could be seen as creating a barrier to interstate commerce. Such a requirement may disproportionately affect out-of-state companies that are engaging in transactions with consumers located in that state. This might deter businesses from conducting sales across state lines due to the additional burden of complying with varying sales tax requirements in each state where they sell products.

Generally, the Constitution seeks to facilitate free trade and movement between states. If a regulation is deemed to impose a significant burden or create an unfair advantage for in-state businesses, it may be struck down as unconstitutional under the Commerce Clause.

The other options touch on different aspects of constitutional law, but they do not directly address the specific issue of interstate commerce as it relates to the collection of sales tax by out-of-state mail order businesses.