CHICAGO -- Barack Obama's campaign announced Sunday a record fundraising haul of $66 million in August, amassing a big advantage over John McCain in the closing stretch of the White House race.

The figure, which smashed the Democrat's February record of $55 million, was announced as Obama prepared for a western campaign swing from Monday and portrayed the Republican as a creature of Washington lobbyists.

"We had a record-breaking month in August -- raising more than $66 million and adding 500,000 new donors," campaign spokeswoman Jen Psaki said ahead of Obama's travel to the battleground states of Colorado and Nevada.

McCain raised $47 million in August -- his best month so far. But the Republican has accepted public financing for his effort, which limits his spending to $84 million until the November 4 election.

Obama is the first presidential candidate to shun public financing, confident that he can keep reeling in small and large donations from his army of givers, which now numbers more than 2.5 million people.

Obama has over $77 million in cash on hand, according to aides, and will seek to press home his advantage through large-scale advertising blitzes and stretch McCain's limited resources across the electoral map.

McCain's campaign has been fired up by the addition of Alaska Governor Sarah Palin as his vice presidential nominee. Polls suggest the hugely expensive race has tightened to a dead heat, making any cash advantage all the more crucial.

Obama has been putting his money to use, launching Saturday a new advertisement, website and series of events in 16 states to highlight how powerful former corporate lobbyists are running McCain's campaign team.

Obama supporters said the initiative was designed to show that the Republican is beholden to vested interests, is divorced from ordinary voters' anxieties and represents a "third term" for President George W. Bush.

Democratic Florida congresswoman Debbie Wasserman Schultz said of Obama's record-breaking take in August, "not a single dollar of those funds were raised or contributed by lobbyists."

"I've been struck by Senator McCain's efforts to embrace the change mantra. I guess imitation is the sincerest form of flattery," she told reporters, while noting McCain's loyalty in his voting record to Bush's policy agenda.

"How is a McCain administration going to change the direction of this country when their administration will be run by lobbyists who are essentially bought and paid for by corporate interests?

"We have to make sure that we return Washington to the people."

Another Obama ad airing from Monday seizes on a Time magazine report that said McCain has tapped Washington "super-lobbyist" Bill Timmons to plan his transition to the White House should he win November's election.

The ad described Timmons as a "consummate insider" who lobbies for oil companies and the credit card industry.

"Corporate special interests rigging the system against hard-working Americans, pushing failed Bush economics. Does that sound like change to you?" the narrator said.

Obama's David Plouffe campaign manager said in a statement: "The 500,000 new donors to the Obama campaign demonstrate just how strongly the American people are looking to kick the special interests out and change Washington."

But McCain, who insists he does feel the economic pain of millions of voters, said in his weekly radio address Saturday that he and Palin had actual records of reform, in contrast to what he called Obama's empty words.

"We offer not only change you can believe in, but change you can verify," the Arizona senator said, satirizing Obama's campaign slogan.