The big money flowing into national politics was supposed to have limits. That at least was the focus on the 2002 campaign finance reforms, which capped donations to both candidates and national parties.
But there is one key exception: the Democratic and Republican conventions, the multi-million dollar affairs which kick off this week in Denver and next week in Minneapolis.
The contributions that fund the massive, four-day affairs come mostly from businesses, unions and other organizations which often have business before lawmakers. And their contributions to the fetes can run into the millions of dollars, unlike money given to candidates, political action committees or national parties.
While many donors tout their sponsorship, by law the host committees don't have to disclose their donors until roughly two months after the convention -- just days before the presidential election. That means that most voters will go to the polls without knowing which interests gave millions to boost the candidates and buy access.
"This is a major loophole that was left in after [the] McCain-Feingold [bill in 2002]," Sheila Krumholtz, executive director of the Center for Responsive Politics, told ABC News.
And the committees are certainly taking advantage of it. Their fundraising strategy has been geared with one clear message: the bigger the donor, the better the access to events and members of Congress.
Brochures for both conventions divide donors by levels of support (gold or silver, for example). In return for their money, corporate sponsors receive a variety of benefits, from advertising opportunities to VIP tickets at events.
And most donations made to the host committees are tax deductible (although the value of the gifts they receive lowers their deduction).
Just how much business gets done at the conventions isn't entirely clear. But whether donors talk business or not, watchdog groups say, their intention is clear.
"They're there to curry favor with the party," Ellen Miller, executive director of the Sunlight Foundation, which tracks convention parties, told ABC News. "You know, you remember a million dollar donor if you're a party leader. And that sticks not just in your bank account to pay for the convention. But it sticks in your mind, as well."
Early estimates already put the cost of the two conventions north of $112 million – much of that from companies with significant lobbying operations in Washington D.C., according to the nonpartisan Campaign Finance Institute.
Indeed, at least 173 organizations – largely companies and trade unions – have given money to the conventions so far. Of those, 48 have given to both party conventions. Those 173 companies have spent $1.3 billion in lobbying expenditures over the past three years, according to a report by the Campaign Finance Institute. And during that same period, those companies' political action committees and employees have contributed $180 million to federal candidates and political parties – all perfectly legal.