Senate Minority Leader Harry Reid (D-Nev.) again invited billionaire and megadonor Stephen Bing to an exclusive luncheon of Senate Democrats just off the chamber floor last week where the group was plotting message strategy for the 2006 campaign.

It was the second time in three weeks that Bing, who gave more than $14 million to Democrats and liberal groups pushing for Democratic candidates in the 2004 campaign, was given such extraordinary access to Senate Democrats inside the Capitol as they went through the lengthy process of revamping their message strategy.

At the meeting, Bing sat at a table with Sens. Edward Kennedy (D-Mass.) and Jay Rockefeller (D-W.Va.), among others, and listened to a series of presentations by Senators and a Who’s Who of top Democratic campaign operatives attempting to instill discipline in their message delivery.

According to numerous Senators and top aides, Bing did not offer a word of advice to the Senators on Thursday or at the previous special caucus on messaging, held Sept. 21.

Reid’s aides and other Senate Democrats said there is nothing wrong with such a big donor attending meetings otherwise open to only Senators and a few top aides, because Bing is not a lobbyist and is not seeking any favors from Democrats. He is a devoted progressive who is helping them craft their message agenda, they say.

“He has been working with Democratic strategists for years,” said Jim Manley, Reid’s spokesman, who noted Bing helped found Democracy Corps, the nonprofit think tank aimed at boosting the party. “He is a smart progressive who is committed to helping change the direction of this country.”

Democrats said there is no contradiction in hosting Bing at their meetings while lambasting Republicans for being too cozy with their own donors, as Reid did Thursday when he said the GOP in recent years had “opened the Capitol doors and invited their donors and cronies in to help themselves.”

“He is not a lobbyist, and he has no legislative agenda,” Manley said. “The goal here is working with like-minded people and groups like Democracy Corps, who share our common goals.”

Democrats contrast Bing with ex-lobbyist Jack Abramoff, who is the subject of a federal investigation for his dealings with American Indian tribes and providing travel funds to House GOP leaders to destinations such as the Old Course at the Royal and Ancient Golf Club of St. Andrews, Scotland.

“He’s just really interested in making this country better, so he’s involved in that,” said Sen. Barbara Boxer (D-Calif.), whose campaigns and political action committee have taken in at least $14,000 from Bing in the past three years.

“He goes way beyond writing checks,” said Minority Whip Dick Durbin (D-Ill.), who added that Bing advises them on “what he is hearing among business leaders.”

“We have conversations with him regularly about what we can do to reclaim the majority,” Durbin said. “He has been a very valuable asset to us.”

Bing was not introduced at the meetings, and some Senators and aides in attendance weren’t even sure who he was.

“I think that’s the guy I saw — I think that’s him,” said Sen. Carl Levin (D-Mich.).

In his Hollywood casual attire, Bing does stand out in the meetings, wearing a T-shirt, jeans and sneakers. He wore a blazer atop his outfit on Thursday.

It’s unclear what advice Bing has been offering to the Democrats. He has no background in political training, and no apparent history in crafting message. Profiles of him in other publications list no background in marketing.

Other guests at the message meetings have included top operatives from the past four Democratic presidential campaigns, including Paul Begala, John Podesta and Doug Sosnik. Reid’s top consultant, Jim Margolis, has attended both meetings as well.

“There’s a big cadre of people in there,” said Kennedy, who said he didn’t speak to Bing on Thursday.

These two meetings differ from the usual weekly luncheons held on Tuesdays; instead, these meetings were held on other days of the week — Wednesday and Thursday, respectively — and are part of the caucus’ evolving plan to be more aggressive with its message and agenda heading into the midterms.

Aides said another reason Bing was able to attend these meetings is because of his ties to Democracy Corps, created by Democratic operatives Stanley Greenberg, James Carville and Bob Shrum. These aides said that as a founder of the group Bing deserved to be in the meetings, considering Greenberg was one of the presenters at Thursday’s meeting.

However, Bing is not listed anywhere on Democracy Corps’ Web site as a founder. In fact, his name is nowhere on the site for the group, a 501(c)(4), whose financial backers are not publicly disclosed.

Democratic aides acknowledged that Bing is considered one of the big funders of Democracy Corps. According to tax filings viewed by PoliticalMoneyLine, the organization took in $1.2 million in 2003.

Approached after the Sept. 21 Senate Democratic meeting, Bing declined to comment on his role in helping craft the strategy. He said he has never agreed to an interview in his life.

Bing, 40, inherited a family fortune made on apartment houses in New York in the 1920s, according to press reports. His father, Peter Bing, sits on the board at Stanford University and is one of the university’s largest donors. Stephen Bing owns a movie production company called Shangri-La Entertainment, with a handful of movies, including 2004’s “Big Bounce,” to his credit in the past 12 years.

He also boasts a few writing credits, including a 1993 erotic thriller “Every Breath” starring Judd Nelson and a 2006 picture currently in production called “Why Men Shouldn’t Marry,” according to the Internet Movie Database.

Of late, Bing mostly has focused on Democratic and liberal causes, transforming himself into one of the single biggest progressive donors in the nation alongside financier George Soros.

In the 2004 cycle alone, he gave $14 million in soft money to 527 organizations, all of which were liberal groups backing Sen. John Kerry’s (D-Mass.) presidential campaign, according to PoliticalMoneyLine.

That total included almost $12 million to the Joint Victory Committee, which funneled its money to the two largest liberal 527s, America Coming Together and the Media Fund.

In the 2002 cycle, just before such unlimited donations were outlawed for national party committees, Bing gave $8 million to the Democratic National Committee.

Bing initially had been a big supporter of John Edwards’ (D-N.C.) presidential campaign, giving the former Senator’s PAC more than $800,000 in soft-money donations in 2001 and 2002.