Eager to avoid a repeat of his party’s 2009 debacle, Nassau County Democratic Committee Chairman Jay Jacobs last summer commissioned his staff to begin opposition research of Mangano. Among the areas he directed them to probe were the county’s GOP political clubs. Republicans control 70 different clubs in Nassau, and Jacobs had a hunch that if his team examined the campaign filings for every single one of them, they might be able to uncover a vulnerability to exploit in the coming election year.

“When we pulled all of the clubs, we noticed 69 of them had normal traffic, if you will. They bring in $7,000, $12,000, $19,000, and they spend about the same,” Jacobs said. “The Hicksville Republican Club caught our attention, and we began looking back. The average [amount of total annual contributions the club received] over 10 years, in and out, was $29,000 a year. In the year that Mangano became county executive, it jumped to $111,000, which was way out of line with everything else.

The following year, which was last year, it jumped to [over $300,000]. That was extraordinary, so of course the question was ‘What the hell is going on in Hicksville?’ ” Political clubs have long been a staple of Nassau County’s various towns and villages. Primarily they are utilized as vehicles for raising money and building up support for a party. Those clubs that are registered as political committees-Hicksville is registered as a constituted county committee-fall under the purview of the state Board of Elections when it comes to fundraising and spending practices.

Sources familiar with these clubs say they typically don’t raise more than between $5,000 and $10,000 a year, and rarely have an actual physical headquarters. The Hicksville Republican Club, for instance, meets at a local Veterans of Foreign Wars post on the second Friday of every month. “It’s something that I’ve only seen in Nassau, but a lot of elected officials who may also be party leaders, who are very associated with a particular community, will tend to use clubs as a fundraising mechanism,” Kremer said.

The Hicksville club has been led by Chief Deputy County Executive Walker, a former assemblyman, since 1999. After averaging over $29,227 per year in total annual contributions from 2006 to 2010-the year Mangano and Walker took office-the club’s contributions grew to $111,835 in 2011. Last year contributions to the club more than tripled, to $363,255, including over $6,000 from companies that had received contracts from the county for Sandy cleanup.

Concurrently, expenditures reported by the Hicksville committee also rose dramatically. Between 2006 and 2010 the club reported a combined total of $120,546 in campaign-related expenditures, but that number shot up to $109,710 in 2011 alone. The following year that amount more than tripled, to $349,093. Among the committee’s outlays, as the Daily News first reported last August, was a $204,000 payment in 2012 to MetLife Stadium, home of the New York Giants and Jets, for a luxury suite used for two separate Mangano fundraisers.

“I’m amazed they spent 200 grand on a skybox. I’m blown away by that,” said a Republican campaign strategist who requested anonymity so as not to hurt his business. “I can’t think of a single other political candidate or entity other than a national party paying for a skybox for something. That’s a lot of money.” An email invitation sent by Friends of Ed Mangano, Mangano’s campaign committee, which Walker also heads, invited individuals to the stadium for “the chance to pilot one of your automotive dreams,” in this case a Ferrari F430 or a Lamborghini Gallardo; a specially designed autocross track allowed attendees of the event to race the cars around the stadium.

The cost to attend the event, according to the invitation, was $1,000 per person, and donors were instructed to make out their contributions to Mangano’s campaign committee. The Hicksville committee also sponsored a fundraiser at MetLife Stadium last September, in that instance for three nights of Bruce Springsteen and the E Street Band concerts. The invitation, sent by Walker from his campaign email address, offered 20 tickets for each night at $1,100 per person, a price that included food, drinks and limo transportation to the venue.

Again, the invitation instructed attendees to make their checks payable to the Mangano campaign. It is unclear whether Mangano’s campaign used the luxury suite for which the Hicksville committee paid for any of that season’s Jets or Giants games-two preseason games and eight regular season games were included in the price. Mangano’s 2012 campaign filings show three separate payments to MetLife Stadium, however: $16,800 for “consulting,” and two other payments, for $2,550 and $960, listed as “fundraisers.”

Neither Mangano nor Walker returned any of several phone and email requests for comment on this story. Brian Nevin, a spokesman for Friends of Ed Mangano and for the Nassau County Executive’s office, did respond, saying the events held at Giants Stadium were reported as an inkind contribution from the Hicksville committee to the Mangano campaign. Nevin pointed to what appears as an unitemized $48,000 contribution from an entity labeled “Anonymous,” as proof of the Mangano campaign’s payment for the luxury suite.

Jacobs finds this explanation dubious. “They had three different fundraisers using that box. There are 10 games at the stadium, two preseason, eight regular season games, there were concerts and other events that the box was available for, in addition,” Jacobs said. “Who sat in the box the rest of the time? Was it empty?”