If you've read anything about political fundraising recently, you may be familiar with this number: $2,300.
That's the most you can give a presidential candidate to spend during the primary election phase of a campaign. You can give another $2,300 during the general election. So how is it that McCain can ask supporters for $50,000 tonight?
"The campaign participates in a joint finance effort with the RNC [Republican National Committee] and the state Republican Party," McCain spokeswoman Crystal Benton explained.
The joint effort is called McCain Victory '08, and it allows donors to write one check that then is divvied up between the campaign and various levels of the Republican party.
Each of those entities has its own donation limit. Add them all together, and it means instead of being limited to a $4,600 contribution to support McCain, donors can give as much as $70,000, more than most Americans make in a year.
"The first $2,300 goes to John McCain 2008," Benton said. "The next $2,300 goes to the compliance fund. The next $28,500 goes to the RNC, and the balance of up to $37,000 is divided evenly between Colorado, Minnesota, New Mexico and Wisconsin state party federal accounts."
Minnesota is one of four states the McCain campaign has singled out for special help this year. All four states are expected to be political battlegrounds.
So the victory fund encourages big donors from all over the country to support Republican candidates in the state, including McCain's Minnesota effort, as well as U.S. Sen. Norm Coleman and Republican congressional candidates.
Benton says the Republican National Committee and the state party can spend the money on all kinds of things: "Get out the vote efforts, grass roots organizing, phone banks, door-knocking -- things like that -- the political ground game."
They can spend the money on advertising, too, of course. And McCain isn't the only one doing it. Presumptive Democratic nominee Barack Obama also has a joint fundraising arrangement with his national party.
"It's a common tactic," said Steve Weissman, Associate Director for Policy at the non-partisan Campaign Finance Institute in Washington. "It's not an egregious violation of established practice."
But Weissman still finds these joint fundraising arrangements troubling.
"It's against the spirit, but not the letter of campaign finance laws, which try to say: Look, we're not going to have a situation where a donor can go to a candidate and say 'Hey! I gave you $70,000!'" Weissman said.
McCain spokeswoman Crystal Benton sees nothing wrong with the McCain Victory '08 fund, and she says her candidate is beyond reproach when it comes to getting the money out of politics.
"Sen. McCain has been a leader in campaign finance reform and in removing the influence of special interests in the political process throughout his career in Congress," Benton said.
In 2002 McCain co-sponsored a law that became known as the McCain-Feingold Act. The act made it illegal for corporations and unions to make unlimited contributions to political parties like they used to.
That so-called "soft money" now gets spent through outside groups. Two of the organizations that made a big splash in the last presidential election, Moveon.org and Swift Boat Veterans for Truth, were both outside groups that spent soft money.
But there is another way that companies, labor unions and wealthy individuals can spend big bucks to support the political party of their choice this year.
They can donate as much as they want to the committees organizing the Democratic National Convention in Denver and the Republican National Convention in St. Paul.