Amendment XIX.
1 The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any State on account of sex.
2 Congress shall have power to enforce this article by appropriate legislation.
Amendment XXVI.
1 The right of citizens of the United States, who are eighteen years of age or older, to vote shall not be denied or abridged by the United States or any state on account of age.
2 The Congress shall have power to enforce this article by appropriate legislation.
Amendment XXIII.
1 The District constituting the seat of Government of the United States shall appoint in such manner as the Congress may direct: A number of electors of President and Vice-President equal to the whole number of Senators and Representatives in Congress to which the District would be entitled if it were a State, but in no event more than the least populous State; they shall be in addition to those appointed by the States, but they shall be considered, for the purposes of the election of President and Vice-President, to be electors appointed by a State; and they shall meet in the District and perform such duties as provided by the twelfth article of amendment.
2 The Congress shall have power to enforce this article by appropriate legislation.
And of course,lest we forget:
Amendment XIV.
1 All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside. No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws. ...
Seems like a big conflict of interest, or elitism.