In the 1895 case of Campbell v. Porter, the United States Supreme Court addressed a dispute over land ownership in Colorado. The plaintiff, Campbell, claimed that he had acquired valid title to certain lands through preemption rights under federal law and sought to eject the defendant, Porter. However, Porter argued that he held superior title due to a subsequent patent issued by the government. The lower court ruled in favor of Porter and this decision was upheld on appeal. The Supreme Court affirmed these rulings based on its interpretation of relevant statutes governing public lands at that time. It found no evidence indicating any irregularity or fraud associated with issuance of the patent to Porter which could invalidate his claim; therefore it concluded that his title superseded any potential preemption rights previously established by Campbell. This case underscored principles regarding priority and validity of land titles under U.S law - specifically highlighting how later patents can override earlier preemptive claims if they are properly executed without fraudulent intent or procedural error.

In the dissenting opinion for Campbell v. Porter, it was argued that the majority's decision to uphold a state law requiring all voters to pay a poll tax violated the Fourteenth Amendment of the U.S. Constitution, which guarantees equal protection under the law. The dissenting justices believed that this requirement disproportionately affected poor and minority voters who were unable or unwilling to pay such a tax in order to exercise their right to vote. They contended that voting is an essential aspect of citizenship and democracy, not a privilege subject to taxation by individual states. Therefore, they concluded that any laws imposing financial barriers on voting are inherently discriminatory and unconstitutional.