Which constitutional clause can be invoked to challenge burdens imposed by residency requirements?

The Equal Protection Clause can be invoked to challenge residency requirements because it prohibits states from denying any person within its jurisdiction the equal protection of the laws. This clause is often applied in cases where state laws have a discriminatory impact on certain groups, including individuals based on their residency status.

When a residency requirement places an unfair burden on individuals moving between states, they may claim that such requirements violate their rights to equal treatment under the law. Courts have utilized this clause to assess whether residency laws are justified and whether they serve a legitimate state interest without disproportionately affecting non-residents.

In contrast, while the Supremacy Clause pertains to conflicts between state and federal laws, the Commerce Clause addresses interstate commerce and could be used in some contexts around residency issues, it is not specifically designed to tackle issues of equal protection. The Due Process Clause deals with fundamental rights and fair legal procedures, but it does not explicitly address issues of equality based on residency. Therefore, the Equal Protection Clause is the most applicable for challenging residency requirements.