One look at the smiles on Hill staffers' faces and you would've thought Christmas came early this year.

But it wasn't Santa delivering the goodies—it was the Cato Institute. And it wasn't presents causing the commotion—it was a royalty-like spread of food, a rarity on Capitol Hill since stringent lobbying standards were passed.

Dozens of chicken sandwiches paired with dozens more tuna sandwiches; bags of chips, pretzels and popcorn; bowls full of fruit; buckets full of soft drinks; and an assortment of holiday candy were used to lure hungry Congressional staffers to a Halloween Cato briefing about why U.S. sugar policy should be dismantled.

One attendee of the briefing was so overcome with excitement he said it felt like he was in the media room at a Washington Redskins' game.

Of course, the irony was, for it to be a "media" room, at least one media member would be present. This day, Cato didn't allow press into its Hill briefing; only "media inquiries."

Perhaps they were keeping reporters out because of an even bigger irony: Cato was essentially lobbying the Hill on farm policy even though Cato is a "think tank" that claims it doesn't lobby.

However, the similarities between Cato and lobbyists are pretty hard to ignore.

Cato aggressively pushes a legislative agenda on the Hill and employs former legislative staffers to do it, just like any big K Street firm.

In fact, Cato's main speaker at the sugar policy briefing previously worked for a former Congressman—a lawmaker turned lobbyist whose brother is coincidently on the payroll of a lobbying coalition designed to eliminate sugar policy.

Some would argue just like a lobbying shop, Cato profits from its actions by advancing the interests of their large corporate donors.

Cato's rhetoric against sugar farmers is no surprise considering the think tank's 2007 annual report lists Altria (formally known as Phillip Morris, of Marlboro Man fame) as a major corporate sponsor. Altria has been a large sugar buyer in the past and a longtime opponent of U.S. sugar policy.

The think tank has even been linked to arguably the best-known lobbyist of all time. A December 2005 Business Week article showed that a senior fellow at Cato accepted money from disgraced lobbyist Jack Abramoff to write as many as 24 op-eds favorable to Abrahmoff's clients.

Despite its ties to the lobbying world, Cato would bristle at the very notion of being considered a lobby. They do not have registered lobbyists on staff and even told the IRS in their 990 filing, "at no time during the year did (Cato) attempt to influence legislation or influence public opinion on a legislative matter." After all, doing so could cause serious tax implications.

Cato is not alone in occupying this vast gray area. Another think tank, the Heritage Foundation, has been an ardent opponent of farm policy over the years and has engaged in lobby-like activities to promote its agenda.

They too have sworn to the IRS they have never "attempted to influence national, state, or local legislation," even though they've penned at least 10 anti-farm policy reports (including "Seven Reasons to Veto the Farm Bill" and "Scrap the Senate Farm Bill and Start Over") and have a former Congressman on staff who has written pieces like "Ethanol Policy Threatens to Starve the World."

According to IRS documents, Heritage spent approximately $8 million in 2007 on "government relations" to "distribute [Heritage] research product to Members of Congress, congressional staff, policy makers in the executive branch of the federal government...[and on] hundreds of briefings for administration officials, lawmakers and their staff."

But Heritage doesn't do all of their briefings in-town. The organization has spent over $313,000 since 2000 on Congressional travel, according to LegiStorm, including "fact finding missions" and "education conferences" for Members, spouses and Hill staff to destinations like New Orleans, Colorado Springs and Los Angeles.

There's even a Congressional Fellows Program to train Hill staffers and "boot camps" designed to teach computer assisted research and reporting skills to journalists, ensuring Heritage's voice will be heard for years to come.

How do they pay for it all? Like Cato, corporate sponsors play a significant role. And Altria is at the top of this list, too.

Sounds like a well-oiled lobby...I mean, think tank.