Congress has the power to pass any law to enforce this amendment. what words tell you that.look at amendment 24

24th amendment "The right of citizens of the United States to vote in any primary or other election for President or Vice President for electors for President or Vice President, or for Senator or Representative in Congress, shall not be denied or abridged by the United States or any State by reason of failure to pay any poll tax or other tax.The Congress shall have power to enforce this article by appropriate legislation."

look at the bold

Created in 1924 by the Rogers Act, the Foreign Service combined all consular and diplomatic services of the U.S. government into one administrative unit. In addition to the unit's function, the Rogers Act defined a personnel system under which the United States Secretary of State is authorized to assign diplomats abroad.