Last night, reporters in Tampa idled by the cancellation of the first night of the Republican convention ran into oil mogul David Koch at a local restaurant. One got a photo:

— Matt Laslo (@MattLaslo) August 28, 2012

(Shortly afterward, a staffer with Koch asked that the reporters not reveal their location to “your ‘Occupy’ friends.”)

A Koch spotting at the convention should not come as a surprise. The convention exists for three reasons, in decreasing order of importance: to generate several days’ worth of live prime-time television coverage, to create a way for donors and candidates to mix and mingle, and to set a party platform and nominate a candidate.

Over the weekend, The New York Times looked at that second element, the ecosystem of donors and parties and events and giveaways that surrounds each convention.

When thousands of delegates, elected officials and party leaders begin arriving in Tampa, Fla., for the Republican National Convention, hundreds of lobbyists, corporate executives, trade associations and donors will be waiting for them, exploiting legal loopholes — and the fun-house atmosphere — that make each party’s quadrennial conventions a gathering of money and influence unrivaled in politics.

In many ways, their activities amount to a parallel convention, one in which access to elected officials, party leaders and delegates provides corporations, interest groups and lobbyists a chance to advance their causes as the party goes about its official business nearby.

Lobbyists and trade groups, virtually all with business before Congress and federal agencies, are paying for a nonstop schedule of beach parties, concerts and cocktail hours.

The host committee website lists some donors: Chevron, Ford, Microsoft, Red Lobster. Bloomberg names others, including Duke Energy.

But the checks are in some ways less important than the alcohol-dampened gatherings. The Times lists some event sponsors:

The American Petroleum Institute, an industry group, will present a concert and panels to promote its “Vote 4 Energy” campaign, including the approval of the Keystone XL pipeline, opposition to new transparency rules for American energy companies operating abroad and the expansion of oil production on federal land.

… Chesapeake Energy, which has lobbied state and local officials to block proposed restrictions on natural gas extraction, has provided [GOP officials with] sport utility vehicles that use natural gas.

AP lists more (very diverse) event sponsors:

Among those sponsoring events in Tampa are Anheuser-Busch, the St. Louis-based producer of Budweiser and other beer brands; pharmaceutical giant Merck & Co. and the Lifetime Television Network. Elliott Management Corp. hedge fund co-founder Paul Singer, who gave $1 million to a super PAC backing Romney, is also co-sponsoring an event aimed at gay Republicans.

Another host is the Personal Care Products Council, sponsor of a “Cocktail and Cosmetics” reception. One of the council’s members is Utah-based Nu Skin Enterprises, a personal care and dietary supplements firm whose vice chairman, Steven J. Lund, was linked to $2 million in donations to the same Romney-leaning super PAC, Restore Our Future.

A “Nightly Lounge” scheduled all week in Tampa is hosted by Politico, the Washington-focused web news operation. The events, which will also be held at the Democratic convention next week, are co-sponsored by defense industry giant BAE Systems, technology designer Intel Corp., liquor seller Diageo and the Coca-Cola Co.

New lobbying rules in the wake of the Abramoff scandal were meant to curtail influence-peddling by lobbyists. It didn’t take long to find a loophole:

The method: Set up a consulting firm to throw your party and honor your favorite members of Congress. Then sell “sponsorships” to the event for as much as $50,000 a pop, thereby allowing lobbyists and their corporate clients to party it up — and curry favor — with lawmakers just as they always have.

This isn’t unique to Tampa. For all of the sponsorships at the RNC, next week they’ll do the same with Democrats in Charlotte. Though the Democrats pledged not to take corporate money, there’s nothing stopping a company from holding a little get-together just off-site.

That face-to-face relationship is vital. Some sponsors, like Politico, are buying visibility, but most are buying access to a captive audience of nearly every important (and unimportant) Republican in America. What most people misunderstand about money in politics is that corporations and lobbyists aren’t buying votes — they’re buying relationships. They’re making it impossible for a congressmember’s door not to be open. There’s a correlation to how votes turn out, of course, but for these funders a party with face-to-face interaction is far more valuable than just cutting a check.

Who was David Koch dining with last night? Sen. Ron Johnson (R-Wis.). They probably weren’t even talking politics. But next time Koch picks up the phone, he can feel pretty confident that Johnson will answer.

A hurricane hit Tampa after all: A storm of money. Hurricane Benjamins.