How close to equal size must districts be in order to meet the one man one vote requirement while not contravening permissible state policies?

For State Legislative Re-Districting, No Bright Line or De Minimis Rule exists. The test is whether the attempt to approach 0 deviation is honest and practicable given permissible state-specific policy considerations. But for Local Government Re-Districting, the Requirement for Equal Representation is More Stringent

In Reynolds v Sims 377 US 533 (1964), at page 562 the court said:?

… Especially since the right to exercise the franchise in a free and unimpaired manner is preservative of other basic civil and political rights, any alleged infringement of the right of citizens to vote must be carefully and meticulously scrutinized.

At page 577 the Reynolds court continued:?

…the equal Protection Clause requires that a state make an honest and good faith effort to construct districts, in both houses of the legislature, as nearly of equal population as practicable.”?

The court reaffirmed this position in Mahan v Howell 410 US 315 (1973). At pages 323 – 327, the court found that a deviation of 1.8% from the ideal was not justified by a need for such absolute equality since the attempt resulted in dilution in voting power of Scott County to “almost nil” and Virginia Beach residents claimed they had been effectively disenfranchised. Ibid p 323 The court then went on to approve a plan with a total 16% deviation (i.e. +/- 8% from 0) on the basis that state plans for redistricting are not to be judged under the requirements of Article 2 §2 but under the Equal Protection Clause. It further stated that lower courts determinations as to what is considered adequate in any one case are not helpful in other cases since all cases are so fact-specific. It stated that 16% deviation presented in this case may be approaching a limit of tolerance but that the goal of not emasculating equal protection was met and the state’s concern about equal representation of votes as presented through its government subdivisions (counties and independent cities) to the legislatures was a rational state concern.

In Kirkpatrick v Preisler 394 US 526 (1969) at page 530, the Supreme Court stated with regard to Legislative Apportionment,?

[We] reject Missouri’s argument that there is a fixed numerical or percentage population variance small enough to be De Minimis and to satisfy without question the ‘nearly as practicable standard’. The whole thrust of the ‘as nearly as practicable’ approach is inconsistent with the adoption of fixed numerical standards which excuse populations variances without regard to the circumstances of each particular case.

In Brown et al v Thomson, Secretary of State of Wyoming, et al, 462 U.S. 835 (1983) at page 842, the Supreme Court stated it has found that a deviation in legislative districts population of less than 10% are insufficient to make out a prima facie case of invidious discrimination under the Fourteenth Amendment.?

In Harris v Arizona Independent Redistricting Commission, 136 C Ct. 1301 (2016) the Supreme Court held that a less than 10% overall deviation was not sufficient evidence in and of itself that the one man one vote rule had been impermissibly violated resulting in slighting of Republican voting power. The defendants produced evidence that the reason for the variation was to satisfy its obligations under section 5 of the Voting Rights Act.?

In Avery v Midland County (1968) 390 US 474 at pages 484-485, the Supreme Court announced, “the Constitution permits no substantial variation from equal population in drawing districts from units of local government having general government powers.”

In Hadley v Junior College District 397 US 50 (1970) at pages 54-56, the US Supreme Court announced the one person one vote principal necessitates that each district within the local government of any kind that is run by elected officials “must be established on a basis that will insure, as far as practicable, that equal numbers of voters can vote for proportionally equal numbers of officials.” Thus, the “as far as practicable” test for equality stands for apportionment of city wards.

In Silver v. Reagan (1967) 67 Cal.2d 452, at page 458, the California Supreme Court stated “deviations from equality cannot be presumed valid but must be justified by a specific showing that a permissible state policy is thereby promoted.”?

In Calderon v City of Los Angeles 4 Cal. 3d 251 supra at pages 269-271, the California Supreme Court adopted the “as far as practicable” test of the foregoing US Supreme Court cases.

The California Legislature has declared those state policies it wishes to promote during re-districting as per Election Code §§ 21601(c-d), 21621(c-e) and 21500(c-d).