Please cite the specific article or amendment in the US Federal Constitution that explicitly gives citizens the right to vote.
The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any State on account of race, color, or previous condition of servitude."Citizens shall not be denied X" is as strong as rights are expressed in the Constitution.
This is like saying the Constitution doesn't give people the right of free speech because it's expressed in a negative rights way (govt shall not impede)
All this was high school civics stuff - did you get to take such a class? I know high school in America is all over the place.