On August 13, 2007, John McCain filed paperwork with the Federal Election Commission, to establish his interest in receiving primary season matching funds. Later he demonstrated that he had qualified (by raising more than $5,000 from each of 20 states). However, he never accepted primary season funds. If he had received them, he would have been required to limit his spending during the primary season (which runs all the way until September 1, 2008) to $56,757,500.

On February 25, 2008, the Democratic National Committee filed a complaint against McCain with the Federal Election Commission, charging him with violating the federal campaign finance law. Specifically, the Democrats complained that McCain had spent more than $56,757,500. Although the Democrats agree that McCain never actually took primary season matching funds, they argue that since he benefited from being eligible for the funds, and since the FEC never voted to release him from the primary season matching funds program, therefore he ought to obey the spending limit. The benefits McCain received from being eligible for primary season matching funds were that he was put on the presidential primary in Delaware and Ohio automatically (otherwise he would have needed petitions). Also the Democrats say that McCain received a bank loan based on his eligibility, although this is disputed.

On April 14, the Democratic National Committee sued the FEC, because the FEC had taken no action on the Democratic complaint. But on May 14, U.S. District Court Judge John D. Bates dismissed the lawsuit, because no one is permitted to sue the FEC until 120 days after filing the original complaint with the FEC. Now, on June 24, the 120 days are up, so the Democratic National Committee has re-filed. The case is again assigned to Judge Bates. The case is Democratic National Committee v FEC, 1:08-cv-1083, in Washington, D.C. Judge Bates is a Bush Jr. appointee.