"No Person shall be a Representative who shall not have attained to the Age of twenty five Years, and been seven Years a Citizen of the United States, and who shall not, when elected, be an Inhabitant of that State in which he shall be chosen."
Comment: This section deals with the qualifications for becoming a member in the House of Representatives. To that end, the Framers determined that the following three qualifications would apply: (1) one must be at least 25 years old (allowing some life experience for a member), (2) one must be a United States citizen for 7 years (to prevent foreign influence), (3) one must be an inhabitant of the state where he is chosen. They rejected property, wealth, and indebtedness qualifications.
This clause was not litigated in court for almost 200 years until the House refused to seat Adam C. Powell because he had allegedly embezzled House funds and lied to the House. Powell sought a judicial declaration of the matter. In Powell v. McCormack, the Court held that although Article I Section 5 provided that "Each House shall be the Judge of the...Qualifications of its own Members," Article 1 Section 2 specifies exactly three qualifications -- age, citizenship, and residency -- and that implies that there can be no more qualifications added by Congress.
In a subsequent holding, the Court ruled in United States Term Limits v. Thornton that the state may not impose its own qualifications. Justice Stevens, writing for the majority, argued that the States can not impose additional qualifications because the Constitution was a creature of the People, and not of the States; and that the States did not retain any power under the 10th Amendment.
Primary Source. The Heritage Guide to the Constitution.