Dudum v. Arntz, 640 F.3d 1098

In 2002, San Francisco adopted Prop A to implement instant runoff voting (IRV) for several city offices, replacing a two-round runoff system.
San Francisco's Charter allows ranking up to the total number of candidates, but authorizes a three-rank limit if equipment cannot feasibly accommodate more, creating a restricted IRV system.
The Department of Elections restricted ballots to three rankings in all IRV elections due to machine limitations and cost concerns.
Dudum and other voters sued, alleging that restricted IRV disproportionately burdens certain voters and dilutes their votes, violating First and Fourteenth Amendments and Civil Rights Act §1983.
The district court granted summary judgment for the City; Dudum appealed challenging the three-rank restriction and its tabulation of exhausted ballots.
The Ninth Circuit analyzed whether the three-rank restriction imposes constitutional burdens and whether City interests justify those burdens.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Does the three-rank restriction burden voting rights?	Dudum argues restricted IRV disenfranchises some voters by preventing full ballot ranking.	City contends the burden is minimal and outweighed by administrative and ballot-management interests.	Burden is minimal; restriction upheld.
Are exhausted ballots a constitutional burden or just accountings of losing votes?	Exhausted ballots effectively disenfranchise voters by ceasing counting later in tabulation.	Exhausted ballots are counted as votes for losing candidates; no substantive disenfranchisement occurs.	Exhausted ballots are counted as losing-vote inputs; no constitutional burden.
Does restriction cause vote-dilution violating one-person, one-vote principles?	Some voters have effectively more influence by ranking multiple candidates,	All ballots carry equal weight at each stage; ranking does not overweight any single vote.	No unconstitutional vote-dilution; weights are effectively equal.
Are restricted IRV’s governmental interests sufficiently strong to justify the minimal burden?	City cannot justify the three-rank limit with compelling interests.	Interests include avoiding voter confusion, maintaining election administration, and saving costs from runoffs.	Interests are substantial and justify the minimal burden.

Burdick v. Takushi, 504 U.S. 428 (U.S. 1992) (flexible standard for weighing burdens on voting rights)
Anderson v. Celebrezze, 460 U.S. 780 (U.S. 1983) (framework for evaluating restrictions on voting rights)
Timmons v. Twin Cities Area New Party, 520 U.S. 351 (U.S. 1997) (lesser burden review; strict scrutiny not required for minimal burdens)
Minnesota Voters Alliance v. City of Minneapolis, 766 N.W.2d 683 (Minn. 2009) (rejected dilution theory in IRV context; votes remain equal in weight)
McSweeney v. City of Cambridge, 665 N.E.2d 11 (Mass. 1996) (exhausted ballots counted as losing-vote inputs; not disenfranchising)