Maine lawmakers could require presidential and vice-presidential candidates to disclose federal income tax returns.
The bill would give candidates three days to release tax returns once a party certifies its nominees. But the requirement wouldn't become effective until more states pass such laws.
Director of Elections Melissa Packard told lawmakers last week such legislation could spur litigation and force printing ballots without a candidate's name if candidates don't promptly provide tax returns after August party conventions.
Such bills are pending in states including New Jersey, New Hampshire, Massachusetts and Pennsylvania.
Similar efforts have failed in California and New Jersey over concerns that it's unconstitutional for states to sets criteria for electing a president.
Democratic Rep. Seth Berry compared requiring candidates' tax returns to signature-gathering requirements to qualify for the ballot.