Some election and legal experts have said the affidavit provision is unclear. It comes immediately before another provision that allows individuals without proof-of-citizenship documentation to register if they sign an attestation that they are a citizen and an election official signs an affidavit saying the person has sufficiently established citizenship. The Election Assistance Commission would create a uniform affidavit for use in that situation.

“Who knows what sort of process they’ll say,” said Alison Gill, director of nominations and democracy at the National Women’s Law Center, a progressive legal advocacy group. “So there is language there, but it’s still very vague and conflictual.”