It looks like FZ is correct. Technically the states could allow only one person to vote in each state for each elector, meaning each representative would then have an equal say (because they each represent one voter).
I see nothing in the linked excerpts of the constitution that makes this scenario impossible.
Given that this is possible, the conclusion is that the right to vote is not guaranteed by the constitution.
Actual practice is irrelevant because the original question is about rights and not the likelihood of being able to vote (which is admittedly about 100%).
Interesting info