The Twenty-Third Amendment grants electoral votes to the District of Columbia. Prior to this amendment, D.C. residents did not vote in presidential elections. Now, D.C. has the same number of electoral votes as the least populated state. A state’s electoral votes are determined by the number of representatives and senators from the state. So, if the least populated state has one representative and two senators, that state has three electoral votes – and so does D.C..
The text of this amendment begins, “The District constituting the seat of Government of the United States shall appoint in such manner as 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;…”