You are incorrect.
The Constitution specifically enumerates the exclusive and unfettered power upon Congress. See Article I, Section 8, Clause 4. The phrase "To establish an uniform Rule of Naturalization, ..." means that ALL rules. Those that need a process to be naturalized, as well as the procedure for such naturalization and those that a citizens at birth (natural born citizens). Thus by saying who is and is not a citizen at birth, Congress is FULFILLING their power under the Constitution.
Further the 14th amendment confers citizenship at birth (i.e without the requirement of naturalization) upon those born on US soil and subject to it's jurisdiction.
Article V, U.S. Constitution: The Congress,whenever two thirds of both Houses shall deem it necessary, shall propose Amendments to this Constitution, or, on the Application of the Legislatures of two thirds of the several States, shall call a Convention for proposing Amendments, which, in either Case, shall be valid to all Intents and Purposes, as part of this Constitution, when ratified by the Legislatures of three fourths of the several States, or by Conventions in three fourths thereof, as the one or the other Mode of Ratification may be proposed by the Congress; Provided that no Amendment which may be made prior to the Year One thousand eight hundred and eight shall in any Manner affect the first and fourth Clauses in the Ninth Section of the first Article; and that no State, without its Consent, shall be deprived of its equal Suffrage in the Senate.
Enacting legislation that changes the Constitution is Unconstitutional. Proposing is not enacting!
The 14th amendment *IS* naturalization. Natural citizens don't need it. Those who need the 14th to be citizens, aren't natural citizens.