President Barack Obama raised more than $42 million for his re-election campaign during the three months that ended Sept. 30, far outpacing his Republican rivals despite the country's economic woes and his own low standing in public opinion polls.

During the same period, Obama also helped the Democratic National Committee raise $27.3 million, pushing his total fundraising for the third quarter of the year to nearly $70 million.

Obama's campaign manager, Jim Messina, announced the figures in an early morning email to the president's supporters. All told, Messina wrote, 606,207 people donated to, including more than 250,000 who had never contributed to Obama's presidential campaigns before. While the Republican candidates remain focused on the early primary and caucus states, the Obama campaign, Messina said, is using its early fundraising to set up campaign offices and build a ground infrastructure for next year's general election.

"That support translates directly to what we can do on the ground," Messina said. "In the past three months we've grown our organizing staff by 50 percent, and opened up three new field offices every week."

The fundraising numbers represent a slight decline for Obama's campaign from what he raised in the second quarter and a larger drop for the Democratic National Committee. But it is far more than any of the Republican presidential candidates appear to have raised over the same period.

Obama and his aides have said they plan to raise hundreds of millions of dollars for his campaign to battle a flood of corporate money that is expected to flow to independent groups raising money on behalf of his Republican opponents. Some of those groups, like American Crossroads, have already spent millions of dollars this year battering Obama with negative television advertisements about his jobs bill and other issues, attacks that are certain to intensify as Election Day nears.

"We're up against a Republican Party and special interest-funded groups that will spend hundreds of millions of dollars spreading any message that they believe will defeat the president and roll back our efforts to build a fairer economy that rewards hard work and responsibility, not large corporations," Messina said in his email.

The campaign is also determined to overcome any disaffection among the president's grass-roots supporters, who provide both small-dollar donations and volunteers for the campaign. In the days before the third-quarter deadline, Obama's campaign inundated his millions of supporters with emails from the president; the first lady, Michelle Obama; Vice President Joe Biden and others, seeking small donations. Some of these appeals informed supporters how many people in their cities or towns had already sent in checks.

The campaign is hoping to surpass the million-donor mark in the coming days, and on Thursday pressed for additional contributions.

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

The Obama campaign said Thursday that of about 766,000 donations the campaign received during the third quarter, about 98 percent came in increments of $250 or less. The campaign did not disclose what proportion of the $70 million joint haul came from such checks, however. While individuals' contributions to Obama are limited to $5,000 for the entire election cycle, checks earmarked for the DNC can total $30,800 per donor.

Gov. Rick Perry of Texas will report having raised about $17 million for the quarter, his campaign has said, while aides to Mitt Romney, the former governor of Massachusetts, have suggested he will report having raised a few million dollars less than that. Rep. Ron Paul of Texas will report having raised $8 million, and the remaining Republican candidates far less.

Republican independent groups, many of them established during the 2010 election cycle, are gearing for a major role in the presidential election to confront any fundraising advantage Obama may have. And supporters of the major Republican presidential candidates, like Perry and Romney, are also putting millions of dollars more into Super PACs that are technically independent of the candidates but were established to aid them.

Obama and the Democratic Party raised a total of $86 million during the second quarter of the year. The drop in third-quarter donations is partly a reflection of the difficulty politicians have raising money during the summer.

But it is also an indication of the political struggles that Obama has had over the last several months. Polls show that large majorities of Americans believe the country is headed in the wrong direction, and that many have soured on Obama's handling of the economy.

Obama also had to cancel about a dozen major fundraisers this summer, including during the tense and lengthy standoff with congressional Republicans over raising the national debt ceiling.