In the case of Pope v. Williams, 1903, the U.S. Supreme Court was tasked with determining whether a Maryland law that required an individual to declare their intent to become a citizen and resident of Maryland two years prior to voting was constitutional. The plaintiff, George T. Pope, argued that this law violated his Fourteenth Amendment rights by denying him equal protection under the laws as he had moved from Washington D.C., declared his intention immediately upon arrival in Baltimore but could not vote due to this requirement. The court ruled against Pope stating that states have broad powers in establishing voter qualifications and residency requirements for voters do not violate federal constitution guarantees or protections such as those found within the Fourteenth Amendment's Equal Protection Clause. The court reasoned that these rules were designed to ensure voters have a genuine attachment and knowledge about their community before they can participate in its governance through voting.

In the dissenting opinion for Pope v. Williams, Justice Harlan argued that Maryland's requirement for a declaration of intent to become a citizen as a prerequisite to voter registration was unconstitutional. He believed it violated the Fourteenth Amendment’s Equal Protection Clause by discriminating against citizens from other states who had recently moved to Maryland and wished to vote there. Harlan pointed out that this law did not apply equally; native-born residents were not required to make such declarations before voting, thus creating an unfair distinction between them and those coming from other states or countries. Furthermore, he asserted that the right of suffrage is fundamental in American democracy and should be protected rather than restricted by state laws like these which impose additional conditions on certain classes of voters.