What legal cases have successfully challenged state documentary-proof-of-citizenship laws and what were the courts’ key findings?

1. Landmark federal precedent: Supreme Court limits state DPOC via the NVRA

The 2013 Supreme Court decision addressing Arizona’s DPOC scheme established that states cannot require additional proof of citizenship for voters using the federal voter registration form because the NVRA preempts state-imposed supplemental requirements for federal elections, a principle courts have repeatedly relied upon when striking down or limiting DPOC enforcement ^{[1] [2] [6]}.

2. Kansas: a high-profile state-level repudiation of DPOC enforcement

Kansas’s experiment with a state DPOC requirement became a cautionary tale after the law was challenged and ultimately struck down in federal court; reporting notes that the statute was overturned and that during its brief enforcement it blocked tens of thousands of otherwise eligible registrants—facts judges cited when finding the law unworkable and disenfranchising ^{[3] [7] [8]}.

3. The federal executive order and League of Women Voters litigation: separation of powers and access

When an executive branch directive sought to force the U.S. Election Assistance Commission to require passports or similar documents on the federal form, courts enjoined implementation, ruling the president and agency exceeded their constitutional authority and emphasizing that millions lack ready access to documentary proof of citizenship while attestation under penalty of perjury remains the baseline for federal registration ^{[4] [5]}.

4. Arizona’s recent roller coaster: partial stays, bifurcation, and last‑minute orders

Arizona’s 2022–2024 litigation illustrates the tension between state laws and federal preemption: the Supreme Court granted temporary relief allowing parts of Arizona’s state-form DPOC enforcement for the 2024 cycle while prior rulings and the 2013 precedent constrained rejection of federal forms, producing a bifurcated system and uneven county-level implementation that courts and commentators warned could cause voter confusion ^{[6] [9] [10]}.

5. What courts repeatedly found: legal doctrines and factual predicates

Across successful challenges, courts have rested decisions on a few consistent findings: the NVRA supersedes state attempts to add requirements to the federal registration form; states have not demonstrated that documentary proof is “necessary” to establish U.S. citizenship; attestation under penalty of perjury is the presumptive sufficiency for federal registration; and executive-action attempts to impose DPOC on the federal form implicate separation-of-powers limits—findings reflected in federal opinions and summarized in legal reporting ^{[1] [2] [4] [6]}.

6. Stakes, evidence of harms, and competing narratives

Voting-rights groups and empirical reports document large numbers of eligible citizens burdened or blocked by DPOC schemes—Kansas reportedly prevented over 30,000 registrations and Arizona’s measures implicated tens of thousands more—facts used by courts to weigh the real-world harms of these laws ^{[7] [8] [11]}. Proponents argue states have authority to protect ballot integrity and some litigants urged judicial deference and relied on Purcell-style timing arguments; the Supreme Court’s temporary interventions in Arizona underscore those competing institutional claims ^[6]. Reporting does not provide every underlying opinion in full here, so this synthesis relies on the cited summaries and filings available in the public record ^{[1] [4] [3]}.

7. Bottom line for litigants and lawmakers

Successful legal challenges have largely succeeded by tying statutory preemption under the NVRA to concrete evidence of disenfranchisement and by invoking constitutional limits on executive action; unless courts rework NVRA precedent or new federal legislation alters the statutory baseline, state DPOC laws will remain vulnerable when they conflict with the federal registration form or impose substantial barriers to eligible voters ^{[1] [2] [4]}.