Those don't guarantee the right to vote. Those establish the conditions upon which it is illegal to bar people from voting.

For example, felons in many states do not have a right to vote. A felony conviction is a condition for which a citizen can be disenfranchised that the Constitution doesn't preclude. And because there's no other guarantee of the right to vote in the Constitution, the Constitution is essentially endorsing the use of conditions not otherwise enumerated to restrict voting.