Turning $12,500 into more than $1 million in less than six months probably sounds tough to most people.

It was for Bobby Mills.

“It is proving difficult,” the little-known gubernatorial candidate from Biddeford said when describing the task of collecting the requisite number of $5 donations – 2,500 – to qualify for up to $1.4 million in campaign funds under the Maine Clean Elections Act.

Mills on Monday withdrew from the Clean Elections program, which provides public money to candidates who agree to abide by certain spending limits.

Mills, who will continue his campaign using private financing, said he found potential donors preferred to give directly to the candidate rather than make their $5 check out to the state fund, as required.

“People can contribute easier now,” said Mills, who became the second Blaine House hopeful – and second independent candidate – to withdraw from the program within a week.

Nancy Oden, an environmental activist from Jonesboro, was the first to enroll in the popular program – and, last Friday, became the first to leave it to pursue a privately funded candidacy.

“I could do it, but it would take all my time, and I have better uses for my time,” said Oden, citing the intensive paperwork associated with the program, which she said favored political insiders.

“It’s a huge advantage for the parties,” Oden said, citing exceptions in the law allowing state parties to print certain literature for their publicly funded candidates.

Political disadvantages are nothing new to independent candidates – particularly those without high name recognition or large bank accounts, according to Jim Melcher, a political scientist at the University of Maine at Farmington.

“It’s useful to have a statewide apparatus to make connections,” Melcher said. “Otherwise, there are a lot of obstacles.”

Money should not be one of those obstacles, say supporters of Clean Elections, which was designed to level the financial playing field in increasingly costly campaigns.

But the system wasn’t designed to replace the need for a broad-based support network, according to Joanne D’Arcangelo, executive director of the Maine Citizen Leadership Fund. She said the two early withdrawals suggest the threshold for qualifying for the program was reasonable.

“It seems to be bearing out that some candidates are realizing they don’t have the breadth of support to participate in a publicly financed system,” she said.

Even with a party affiliation, qualifying is no easy task, said GOP gubernatorial hopeful Maine Sen. Peter Mills of Cornville.

“It’s an extremely difficult thing we’re doing, but we’re doing it very well,” said Mills, who estimated he had half of the required 2,500 donations.

Party candidates have until April 18 to submit their contributions if they want funding before the June primary, and independents have until June 2 to submit their contributions.

As it stands, six of the 12 announced gubernatorial candidates hope to get public financing, with the other six – including incumbent Democratic Gov. John Baldacci – raising money privately from contributors.

Also intending to run clean are Republican Sen. Chandler Woodcock of Farmington; Green Pat LaMarche of Yarmouth; Rep. Barbara Merrill, an Appleton, independent; Alex Hammer, a Bangor independent; and David John Jones, a Falmouth independent.

Private campaigns are being waged by former Republican U.S. Rep. David Emery from St. George; Christopher Miller, a Gray Democrat; and Robert Bizier, an Albion Democrat.

State elections officials estimate that three publicly funded gubernatorial candidates in the general election would cost the state $4.9 million.

The Associated Press contributed to this report.