What Does It Mean?
In a republican form of government voting is representative,
so the number of people represented in every district must be equal for the weight of votes to balance
(see The Representation Question).
That's all "one person, one vote" can mean without placing Amendment XIV over the Guarantee clause.
Rights require parity without priority, unless there's an exceptional circumstance like evidence of discrimination.
But the weight of votes doesn't reflect the population's actual economic balance.
Economic inequality is many times greater today than in 1787,
and the Industrial Revolution increased the impact of this inequality.
Adding an economic factor to redistricting (see Leashing the Gerrymander)
ensures that people in every economic range will be represented in Congress.
With two or three ranges, a district's constituents will have far more economic interests in common
and will be better able to keep their Representative true to their interests.
An economic factor in redistricting
makes self-governance to promote our economic interests
more effective for everyone.
Combining it with a clause safeguarding every person's access to government
keeps a loophole from opening and ends a corrupt practice that already exists.
Article IV, Section 4:
"The United States shall guarantee to every State in this Union
a Republican Form of Government, [...]"
“The right of citizens of the United States to vote […]
shall not be denied or abridged by the United States or any state
by reason of failure to pay a poll tax or other tax.”
This consists fully with the Constitution, detailing the Preamble, Amendment XXIV and the Guarantee clause.
Image, Terrence Hatch