What does the equal treatment clause prohibit?

The equal treatment clause is a fundamental principle in law that ensures all individuals are treated equally under the law, particularly within the context of the Fourteenth Amendment's Equal Protection Clause. This clause prohibits states from enacting laws or policies that unjustly discriminate against individuals or groups based on characteristics such as race, gender, or religion. By ensuring that no individual is treated differently based on these arbitrary classifications, the equal treatment clause upholds the notion of fairness and equality within the judiciary framework.

This principle is vital for safeguarding civil rights, as it provides a basis for individuals to challenge discriminatory laws or actions taken by state governments. Thus, the option emphasizing that states cannot enforce laws that discriminate against citizens directly aligns with the essence of the equal treatment clause, affirming that all citizens are entitled to the same rights and protections under the law.

The other options touch upon related concepts but do not directly define the scope of the equal treatment clause. For instance, the federal government's role regarding state laws or citizens' ability to sue state governments represents different legal principles and protections, while voting rights, although crucial, involve specific statutes and amendments that are distinct from the general equal treatment prohibition.