Obama campaign manager Jim Messina said in an e-mail to supporters that more than 600,000 people donated to the campaign in the most recent quarter, more than the previous three months. He said more than 980,000 people have given money to the campaign, and in the most recent quarter, 98 percent of the donors gave $250 or less, with an average donation of $56.

"Getting to a million grassroots donors isn't just a huge accomplishment this early in the campaign. It's our answer to our opponents, the press, and anyone who wants to know whether the President's supporters have his back," Messina said.

The numbers include $42.8 million for Obama's campaign and $27.3 million for the Democratic National Committee, which will help Obama's re-election effort next year.