The Senate of the United States shall be composed of two Senators from each state, elected by the people thereof, for six years; and each Senator shall have one vote. The electors in each state shall have the qualifications requisite for electors of the most numerous branch of the state legislatures.

When vacancies happen in the representation of any state in the Senate, the executive authority of such state shall issue writs of election to fill such vacancies: Provided, that the legislature of any state may empower the executive thereof to make temporary appointments until the people fill the vacancies by election as the legislature may direct.

This amendment shall not be so construed as to affect the election or term of any Senator chosen before it becomes valid as part of the Constitution.

"Very shortly after ratification it was established that if a person possessed the qualifications requisite for voting for a Senator, his right to vote for such an officer was not derived merely from the constitution and laws of the State in which they are chosen but had its foundation in the Constitution of the United States. 2 Consistent with this view, federal courts declared that when local party authorities, acting pursuant to regulations prescribed by a party's state executive committee, refused to permit an African American, on account of his race, to vote in a primary to select candidates for the office of U.S. Senator, they deprived him of a right secured to him by the Constitution and laws, in violation of this Amendment. 3 An Illinois statute, on the other hand, which required that a petition to form, and to nominate candidates for, a new political party be signed by at least 25,000 voters from at least 50 counties was held not to impair any right under the Seventeenth Amendment, notwithstanding that 52 percent of the State's voters were residents of one county, 87 percent were residents of 49 counties, and only 13 percent resided in the 53 least populous counties." - Findlaw