PORTLAND – Sen. Susan Collins says her Democratic opponent is the biggest recipient of money from the liberal network MoveOn.org, a claim she’s trumpeting to energize supporters and raise money for her re-election campaign.

Collins said MoveOn has funneled more than $365,000 into Tom Allen’s campaign, making Allen the top beneficiary of the group’s fundraising efforts.

“If I asked you who was the biggest recipient of MoveOn, you’d probably say Hillary Clinton or Barack Obama,” Collins told a crowd gathered last weekend in Portland for Republican presidential caucus results. Then she added: “It’s Tom Allen.”

Already, the closely watched contest between Collins and Allen is on pace to be the most expensive Senate race in Maine history.

According to filings with the Federal Election Commission, Collins raised about $4.5 million as of Dec. 31 while Allen took in $3 million. The record of $8 million was set in 2002 when Collins withstood a challenge from Democrat Chellie Pingree.

Eli Pariser, the Maine-born executive director of MoveOn, acknowledged that Collins’ figure was in the ballpark of what Allen raised through the Web site.

But he said MoveOn members undoubtedly have given more to Obama, although his contributions – unlike Allen’s – are not bundled by the group.

Allen campaign spokeswoman Carol Andrews emphasized that the contributions in question do not come from MoveOn, but rather from thousands of individuals who receive e-mails from the organization encouraging them to donate.

She said the money collected for Allen was in “relatively modest amounts,” and Pariser said the donations averaged about $40.

Steve Abbott, Collins’ chief of staff, suggested that her campaign would be using Allen’s MoveOn connection to highlight the senator’s portrayal of herself as a moderate willing to work across party lines to craft solutions.

“The biggest threats to MoveOn and other extreme groups are those who will throw partisanship aside to get something done,” Abbott said Tuesday. “That’s why I think Susan Collins is such a target for them.”

Andrews said Allen won’t be hurt by efforts to make hay out of the MoveOn money, which she said came from individuals who agree with the congressman’s opposition to the Iraq war, his fight against large pharmaceutical companies and his support for the middle class.

But political observers suggest that attempts to tar Allen by identifying him with MoveOn might rally the Republican base and help the senator’s efforts to raise money.

“I’d be stunned if this doesn’t appear in the text of some direct-mail fundraiser. I mean, that’s classic red meat for a direct mailer,” said Mark Brewer, a professor of political science at the University of Maine.

Concerns about Allen’s MoveOn support also could resonate among swing voters and independents who are in sync with Collins’ moderate position on the political spectrum, Brewer added.

Anthony Corrado, a government professor at Colby College, sees less of an impact beyond MoveOn being “a political talking point” for Collins in her dealings with conservative Republicans.

“My sense is that there’s such concern in the state about the real issues that are going to drive this election – the economy, health care and the war – that these types of political comments aren’t going to have much effect on the vote at all,” he said.

Collins’ remarks were not the first in which she crossed swords with MoveOn.

Last fall, Google rejected Collins’ ads containing the key word “MoveOn.org” because of the group’s opposition to use of its trademark name. The ads were aimed at raising contributions to counter what they said was MoveOn’s heavily funded TV ad campaign against the senator.

MoveOn backed away from its stance after Collins objected to what she characterized as MoveOn’s attempt to stifle free speech.

At around the same time, Collins joined in the condemnation of MoveOn for its full-page newspaper advertisement in The New York Times that criticized Gen. David Petraeus, the commander of U.S. forces in Iraq.

In a bipartisan vote, Congress passed a resolution censuring MoveOn for the “General Betray Us” ad, a measure Allen opposed.