"provide public funding for candidates who agree to take no special-interest contributions and abide by strict spending limits" does not always limit influence via private money since private contributions are still allowed - as in Maine.
Hillary was correct to not sign on.
As of June 2007:
http://www.commoncause.org/site/pp.asp?c=dkLNK1MQIwG&b=507399Maine
In November 1996, voters in Maine approved a ballot initiative, the Maine Clean Election Act, establishing a system of public financing and voluntary spending limits for governor, state senator, and state representative candidates. Candidates who raise a threshold number of small contributions from registered voters in their district and agree not to raise any more private money qualify for a fixed amount of public financing for their campaign.
Arizona
In November 1998, Arizona voters passed the Arizona Clean Elections Act, which provides full public funding for statewide and legislative candidates who meet a threshold requirement to raise a certain number of $5 contributions from voters. The public funds come from a variety of sources, including a tax checkoff, voluntary contributions and a surcharge on civil and criminal penalties.
Connecticut
Connecticut adopted its public financing laws in 2006, two years after then-Governor John G. Rowland resigned from office following the disclosure of improper gift acceptances and corrupt practices. The public elections system, paid for by the Citizen’s Election Fund, gives full public financing to candidates for state senator and state representative, as well as governor, lieutenant governor, attorney general, state comptroller, secretary of state, and state treasurer. Connecticut is also beginning a pilot program for the public funding of municipal elections, which began in New Haven with financing for mayoral candidates.
Florida
Under Florida law, candidates for governor and other statewide offices who raise a threshold amount of money and agree to spending limits are eligible for public matching funds. Contributions of $250 or less from individuals are matched 1-to-1 with public funds. Also, if a candidate exceeds the voluntary spending limit, their opponent is eligible to receive additional public funds equal to the amount by which the limit has been exceeded.
Hawaii
Hawaii's public financing system provides funding to all candidates who agree to a voluntary spending limit. Candidates are provided with public funds equaling 10%-15% percent of the spending limit, depending on the office. The source of the funding is general appropriations and an income tax checkoff.
Maryland
Maryland's public financing system provides matching funds (1:1 match) for candidates for governor and lieutenant governor in the primary and general elections. The source of the funds is contributions from taxpayers (add-on) and revenue from fines related to the public financing law. The law has been in place since 1974, but since then only in the 1994 elections has a gubernatorial candidate from a major party opted into the system.
Massachusetts
In November 1998, Massachusetts overwhelmingly (67%) passed a "clean elections" public financing law that provided the option of full public financing for the campaigns of qualified candidates of statewide offices as well as the state Senate and House of Representatives. Ballot initiatives in the state however, cannot include funding for any program and the legislature refused to fund the system. In 2003 the law was repealed. In its place is a much weaker partial public financing law for six statewide offices that provides matching funds for contributions of up to $250 for qualified candidates who agree to specific limited expenditures for their campaigns.
Michigan
Enacted in the 1970s, Michigan's public financing system provides gubernatorial candidates who agree to a spending limit with a flat grant for the general election and a 2:1 match for small contributions (under $100) in the primary.
Minnesota
Minnesota's public financing system was enacted in the 1970s and significantly reformed in 1993. It was the first state to provide public financing for both legislative and gubernatorial candidates and is generally considered one of the most successful campaign finance systems in the country. Candidates who agree to a spending limit receive public funding equal to 50% of the limit. Public funds come from a tax check-off that allows taxpayers to direct those funds to a qualified political party and from an annual appropriation. In addition, a unique program allows anyone contributing up to $50 to a party receives a refund from the state.
Nebraska
Nebraska passed a unique public financing law in 1992. The system provides public funds to legislative candidates who agree to a voluntary spending limit and whose opponent exceeds the spending limit. If sufficient funds are available, statewide candidates may also receive public funds. The source of the funds are primarily an appropriation and contributions by taxpayers from tax refunds.
New Jersey
New Jersey's public financing law was enacted in the 1970s. It provides 2:1 matching funds for both the primary and general elections to candidates who agree to spending limits. The system is funded by an income tax checkoff.
New Mexico
In 2003 New Mexico passed a public financing law for candidates vying for a seat on the Public Regulation Commission, which is responsible for oversight of state public utilities. Similar to the full-public finance laws in Arizona and Maine, candidates who raise a threshold amount of small donations may receive full public funding for their campaigns if they agree not to accept additional private donations. The system is funded by a surcharge on the companies regulated by the commission. In 2007, New Mexico added public financing for candidates for judgeships on the Court of Appeals and Supreme Court of New Mexico.
North Carolina
In 2002 North Carolina passed a public financing law for judicial candidates that goes into effect in 2004. The law is designed to provide full public financing for candidates of the the State Court of Appeals and Supreme Court, provided candidates raise "seed money" from at least 350 contributors between $10 and $500 each. The grants provided to qualified candidates are funded by a tax check-off and $50 voluntary contributions from lawyers when they pay their privilege license tax.
Rhode Island
Under Rhode Island law, candidates for statewide office who raise a threshold amount of money and agree to spending limits are eligible for public matching funds. Candidates are eligible for 2-to-1 public matching grants for contributions of $500 or less and a 1-to-1 match for contributions in excess of $500. Public finance candidates also receive free air-time on community antenna television and Rhode Island public television.
Vermont
In 1997, the Vermont legislature passed a public financing bill that provides a fixed amount of public financing to candidates for governor (up to $75,000 for the primary and $225,000 for the general election) and lieutenant governor (up to $25,000 for a primary and $75,000 for the general election) who raise a threshold number of small contributions and agree not to raise any more private money. In a challenge to the U.S. Supreme Court's 1976 Buckley v. Valeo, the bill also imposes mandatory spending limits on all state and local candidates. The primary source of funding is voluntary contributions of taxpayer refunds; other sources are an appropriation and the revenue from some fees and penalties.
Wisconsin
Wisconsin enacted its partial public financing system in the 1970s. It provides matching funds to statewide and legislative candidates. The system is funded by a tax check-off. In recent years, the system has been damaged by a decline in the amount of funds generated by the check-off and growing spending on independent expenditures and sham "issue ads."