By Dave Sherwood
PORTLAND, Maine (Reuters) - Maine voters on Tuesday approved a measure to revitalize the state's pioneering system of public campaign finance, once hailed as a U.S. model but now suffering from declining participation.
The Clean Elections Initiative had received 54.6 percent of the vote with three-quarters of precincts reporting, the Bangor Daily News and Portland Press Herald reported.
The law would increase public funding for candidates to as much as $3 million. Backers said the law would make them more competitive against privately funded candidates.
The existing law, passed by voters in a 1996 ballot initiative, made up to $2 million available to candidates for statewide office.
The initiative proposes to beef up disclosure rules, requiring political advertisements to list their top three donors. It would also strengthen penalties for violating campaign finance law.
The Maine ballot question underscores the national debate over how best to regulate campaign finance in the wake of Citizens United, the landmark 2010 U.S. Supreme Court case that allowed unlimited independent spending by corporations and labor unions in election campaigns.
Opponents, including Republican Governor Paul LePage, argued that the proposed law did nothing to limit spending by outside groups and called the measure a subsidy for undeserving politicians.
Maine's statewide system of full public financing was the first in the United States. Participation rates have dropped by more than 30 percent since 2006 as outside money has flooded into state elections.
In 2014, independent groups including political action committees spent at least $14 million to sway Maine voters, more than the candidates themselves, according to Maine Ethics Commission filings.
The pattern is the same nationally, according to Katy Owens Hubler, of the National Conference of State Legislatures.
Only Connecticut and Arizona now have programs similar to Maine's, Hubler said.
(Editing by Scott Malone)