Which principles were strengthened by Wesberry v Sanders?

Answer 1

Wesberry v. Sanders, 376 US 1 (1964)

The case continued the validity and renewed judicial enforcement of the "Great Compromise" reached in the Constitutional Convention of 1789 under which each state has two Senators and a number of Congressmen equal to its population selected by districts approximately equal in size. ("Representatives shall be apportioned among the several States according to their respective numbers, counting the whole number of persons in each State..."). In the convention the smaller states insisted upon equal voice with the larger states whereas the larger states insisted upon representation based upon population. Had this controversy not been decided by compromise, the union would not have been formed.

Over the years due to population growth and shifts the districts of the US House of Representatives became more and more disproportionate to the population. State legislators, pressured by their Congressional delegations, failed to redraw the districts even though official census figures showed greater and greater discrepancies. For decades the courts turned a blind eye, unwilling to enter "the legislative thicket" and thus anger the representatives who were very protective of the districts from which they had been elected. This was justified under the concept of separation of powers, but resulted in a breach of the "Great Compromise." It also resulted in the vote of a person in a rural district of Georgia (where the case was brought) being worth three times the vote of a person from metropolitan Atlanta. This case restored the "Great Compromise" guaranteeing that after each decennial census Congressional districts are redrawn based upon population. Thus each person's vote for a Congressman is now approximately equal to every other person's such vote across the states and the nation.

(Note: This is a very simplified answer. I was the plaintiff in the case).