Federal Voting Rights Act of 1965. 
The federal Voting Rights Act (VRA) prohibits racial discrimination in state and local elections in order to enforce the provisions of the Fifteenth Amendment to the United States (US) Constitution.  Section 2 of the VRA (Section 2) prohibits any voting practice or procedure that results in the denial or abridgment of the right to vote on account of race, color, or language-minority status.  Intentional discrimination based on race or color is prohibited, but also prohibited are practices that have the effect of impairing the ability of members of a racial group to participate equally in the nomination and election of candidates.  In these cases, proof of intentional discrimination is not required to show a violation; instead, a violation is established when the totality of circumstances show that the political process leading to nomination or election in the jurisdiction are not equally open to participation by members of a protected class in that its members have less opportunity than other members of the electorate to participate in the political process and to elect representatives of their choice.  Section 2 prohibits both vote dilution and the abridgment of the right to vote.

Vote Dilution.  Federal courts have recognized two primary forms of vote dilution.  First, vote dilution can be caused by the use of at-large voting methods where voters of the entire jurisdiction elect the members to the governing body; the majority by virtue of its numerical superiority will regularly defeat the choices of minority voters.  Second, vote dilution can occur in district-based elections through a method of drawing voting districts that spreads minority votes throughout the districts ("cracking"), or concentrates minority votes into a small number of districts ("packing"), or both, effectively weakening the minority group's ability to elect its candidates of choice. 

Abridgment of Voting Rights.  Federal courts have described an "abridgment" of the right to vote as an electoral system or practice that impairs voting rights on the basis of race, color, or language-minority group regardless of whether there was outright denial of the right to vote.  Some examples have historically included a poll tax or discriminatory literacy tests.  Abridgment of the right to vote can occur regardless of which racial group is in the majority.  Abridgment may also be commonly referred to as vote suppression or vote denial.

Washington Voting Rights Act. 
In 2018 the state enacted the Washington Voting Rights Act (WVRA) to regulate elections in certain counties, cities, towns, school districts, fire protection districts, port districts, and public utility districts (all together, "political subdivisions").  In 2023 the Washington Supreme Court stated that the WVRA expressly protects against two types of voting discrimination:  abridgment and dilution.  A violation of the WVRA is established when a political subdivision's method of electing its governing body exhibits polarized voting and members of a protected class do not have an equal opportunity to elect candidates of choice as a result of dilution or abridgement of their rights.  Polarized voting is shown when there is a difference in the choice of candidate or other electoral choices that are preferred by voters in a protected class or coalition of protected classes, and in the choice of candidates and electoral choices that are preferred by voters in the rest of the electorate. 

Political subdivisions may take corrective action to change their election systems in order to remedy a potential violation of the WVRA, including through implementation of a district-based election system.  If corrective action is taken by the political subdivision by its own accord, it must provide public notice to its residents about the proposed change to remedy the potential violation and hold a hearing.   

Any voter who resides in a political subdivision, an organization whose members or volunteers include a voter who resides in the political subdivision, or a tribe located at least in part in the political subdivision (all together, "party") may challenge the political subdivision's electoral system by filing a notice of intent that identifies the protected class or classes who are affected because of alleged vote dilution and polarized voting.  If corrective action is taken in response to such notice, the political subdivision must obtain a court order certifying that the remedy complies with the WVRA and was prompted by a plausible violation.  Courts apply a rebuttable presumption against adopting a political subdivision's proposed remedy.  If the court approves the remedy, it may not be challenged by a lawsuit for at least four years.  The party filing the notice may make a demand to the political subdivision for reimbursement of the costs incurred in conducting the research necessary to file the notice.  Upon receiving such demand, the political subdivision has 60 days to reimburse the party for reasonable costs up to $50,000.

If, after the political subdivision receives a notice of intent to challenge the electoral system because of alleged vote dilution and polarized voting, the political subdivision does not remedy the alleged violation within 90 days, a party may file an action against the political subdivision in superior court.  To determine whether voting is polarized in a vote dilution claim, the court assesses the elections pragmatically based on local election conditions.  If a violation is found, the court may order appropriate remedies, including requiring the political subdivision to redistrict or create a district-based election system.  The court may award attorneys' fees and costs to a prevailing plaintiff.  Prevailing defendants may be awarded certain costs and fees.  

Cities and towns with a population of under 1,000 and school districts with enrollment under 250 students are exempt from the WVRA but may still voluntarily change their election system to remedy a potential violation. 

The second substitute bill specifies that, for abridgment claims, the existing four-year safe harbor provided under the WVRA is a protection against an action based on the same election policy or practice for which the court concluded that the political subdivision's remedy complies with the WVRA, rather than it being a protection from any cause of action brought against the political subdivision for four years.  Circumstances considered not to be relevant in demonstrating an abridgment claim may not be considered by a court when evaluating such claim.

The current exemption from requirements under the WVRA for cities and towns with a population of under 1,000 and school districts with enrollment under 250 students is extended to apply to the new provisions concerning abridgment claims, except that no such jurisdiction may implement a method of electing the governing body or an election policy in a manner that results in the dilution or abridgement of the rights of voters who are members of a protected class.  It also specifies remedies applicable to a vote dilution claim and an abridgment claim by clarifying that changing a political subdivision's electoral system is a remedy to a vote dilution claim.  In addition, the second substitute bill makes technical corrections such as correcting an internal reference and aligning language in provisions related to vote dilution claims for consistency.  The second substitute bill also adds a null and void clause, making the bill null and void unless funded in the budget.