PORTLAND – The invitation to a recent anti-casino fund-raiser reads a bit like a who’s who of the state’s business and political elite.

The list includes Leon Gorman, chairman of L.L. Bean’s board; Tim Hussey, who runs Maine’s oldest family-owned business; Peter Geiger, whose company publishes the Farmers’ Almanac; Warren Cook, former Sugarloaf USA president; and Gov. John Baldacci.

The $250 per-plate fund-raiser, at the Harraseeket Inn in Freeport, raised more than $85,000, but organizers say much more is needed to fight a proposal for a $650 million Indian casino and resort in southern Maine.

Many of Maine’s big hitters appear to be lining up against the casino, while a major Las Vegas developer is funding the pro-casino effort in what could become the state’s costliest referendum battle ever.

Christian Potholm, a political science professor at Bowdoin College, estimated that both sides have solid 40 percent blocs of voters, and each is vying to sway the undecided 20 percent before the November vote.

“Whatever you’re spending, you’re spending to influence 20 percent of the vote,” he said. “It’ll probably be won or lost on television.”

Despite the potential for big budgets and heavy advertising, both sides are emphasizing their grass-roots credentials, portraying themselves as feisty underdogs battling on behalf of the average Mainer.

Dennis Bailey of Casinos No said he and allies are toiling to raise cash to match the resources of what he described as deep-pocketed casino insiders who will spend whatever is necessary to win in November.

“They’re not raising money,” Bailey said. “They’re simply bankrolled by Las Vegas.”

Documents filed earlier this month with the state Ethics Commission indicate that Think About It, the pro-casino political action committee, has received more than $75,000 in contributions this year.

All those contributions have come from two sources: Thomas Tureen, a Portland lawyer who helped launch the Foxwoods Casino project in Connecticut, and Marnell Corrao Associates, a Las Vegas-based casino developer that is providing architectural and design assistance to the Passamaquoddy and Penobscot tribes.

Marnell Corrao has built some of the biggest casinos in Las Vegas: the Bellagio, Stardust, Mirage, Caesars Palace, Excalibur, MGM Grand, New York New York, and Treasure Island. All told, it has developed about 60 percent of the hotel-casino space in Las Vegas, said Erin Lehane, spokeswoman for Think About It.

The most recognizable name in Maine among casino supporters is former Gov. Ken Curtis, who is Think About It’s co-chairman.

Daniel Wathen, former chief justice of the Maine Supreme Judicial Court, represented the pro-casino group in legal wrangling over the referendum question but has not taken a public position on the casino issue.

Casino backers are not focusing on garnering support from the state’s political and business leaders, Lehane said.

“Our core demographic, the people we’re hearing from, are the real working people of Maine,” she said.

Casino foes, meanwhile, are continuing to solicit small donations from communities in southern Maine and even New Hampshire. Last weekend residents of North Berwick agreed to cut a $5,000 check to Casinos No.

But the anti-casino group’s biggest donations have come from some of Maine’s most recognizable figures.

Nearly half of the $84,000 reported to state officials so far in 2003 has come from the L.L. Bean family. Other contributors include Chris Harte, a former Portland newspaper executive, and Hussey, who is president and chief executive officer of Hussey Seating Co. in North Berwick.

Political support comes from Gov. Baldacci, who spoke at Casinos No’s April 10 fund-raiser, and former Gov. Angus King, who’ll join the anti-casino fight when his family’s cross-country RV trip ends in June.

Casinos No plans to hold additional fund-raisers this summer with the goal of raising a total of $1 million.

“We’re going to try to do a lot of organizing at the grass roots,” Bailey said. “We’re going to have to do more of a guerrilla-style campaign that’s cheaper.”