President Barack Obama’s 2012 campaign claimed last night to have accumulated “450,000 grassroots donors” by 9:32 Central Time.

In 2007, “then-Senator Obama’s campaign had 180,000 grassroots donors,” said a statement on the campaign’s website. “That makes it even more amazing to report that, as of just now, we’ve reached our goal of bringing 450,000 grassroots donors into this campaign,” the statement continued, announcing a new target of 475,000 donors. (Rick Perry generating ‘buzz’ in key primary state of New Hampshire)

However, the site did not report how much these donors had contributed towards the campaign’s quarterly goal of $60 million. The quarter ends today.

The 450,000-plus donors comprise “a very strong mailing list” of people who can later be engaged for subsequent donations and for volunteer work, said Michael Malbin, the director of the D.C.-based Campaign Finance Institute.  It is equal to roughly 10 percent of Obama’s mailing list during the 2008 election, and “is an extraordinarily high number of people this early in the campaign,” he said.

Other elements of the fundraising drive, however, suggest the campaign is facing greater-than-expected difficulties raising funds amid the sour economy and may turn to wealthy supporters to protect against any drop in contributions from small donors.

Democrats acknowledge some difficulty raising funds from donors from business-interests displeased by Obama’s policies, from lower-income people struggling economically, and from people in the Jewish community distressed at the president’s policy towards Israel.

Low-income donors may also be less generous in 2012 than when they were donating to first elect Obama. On June 15 the campaign sent out emails to myriad supporters soliciting $5 donations in exchange for a chance to share dinner with the president. But on June 29, only 38 hours from the end of the fundraising quarter, Obama’s team send out another email soliciting more donors, and offering both Obama and Vice President Joe Biden as dining partners.

“We’re closing the books on the first fundraising quarter of the 2012 race at midnight tomorrow,” the June 29 email said, and then added a hint that the campaign might not reach its fundraising goal.

“A lot of folks will be interpreting our numbers as a measure of this campaign’s support… but they are wrong about why. We measure our success not in dollars but in people — in the number of everyday Americans who’ve chosen to give whatever they can afford because they know we’ve got more work to do,” the pitch said. “I’m asking you to be one of them. Please donate $5 or more before midnight tonight.”

The hint was much broader in a Thursday midday message from the campaign. “The next few hours are critical for us… anyone worth their salt in politics knows tonight is one of the most important tests we’ll face as a campaign this year. Let’s hit it out of the park.”

The Obama campaign is also asking wealthy donors to give all their permissible political donations to the campaign’s Obama Victory Fund. The find is a “one-stop-shop” way for people to donate the maximum of $2,500 to Obama’s primary campaign, $2,500 to his general election campaign, and the maximum to other political committees, Malbin said. The most Obama’s one-stop-shop can ask for from any single donor is $75,800 per year, Malbin said.

But some of this maximum must be allocated to Democratic congressional committees, not the Obama campaign, he said. That means that roughly $15 million of Obama’s $60 million target has to be spent by party, not by Obama’s campaign, Malbin said.

At the end of winter, the Democratic National Committee had $6.1 million in the bank and the Republican National Committee had $724,654 in the bank, according to data released by the Federal Election Commission on May 20.

Obama’s campaign officials say they hope to raise $750 million or more for the campaign, in which Obama will have to pull out every stop to win in a tough economy. No president since Franklin D. Roosevelt in 1936 has won reelection with unemployment above 9 percent.

To bring in all that money, Obama has begun a record-setting fundraising drive.

For example, he has already attended more than 30 fundraisers, and has two more planned for June 30 in Philadelphia. Last Thursday, he attended three fundraisers in New York. At the first fundraiser, roughly 600 people paid $1,250 a plate. The second fundraiser drew roughly 60 people for $38,500 a plate, and the third fundraiser drew roughly 1,400 people for a price of at least $100 a ticket.

First Lady Michelle Obama is also raising funds for the campaign, and recently headlined at least four fundraisers in California.

In contrast, President George W. Bush had attended only a handful of fundraisers during the same period of his 2004 reelection campaign. In the second-quarter of 2003, he raised $35.1 million, according to Malbin’s institute.

A large percentage of Obama’s donations are expected to come from a smaller pool of wealthy donors, such as the Wall Street wealthy that attended the New York fundraiser.

During the 2008 primary season, 30 percent of Obama’s funds came from donors who gave $200 or less, in one or several donations, said Malbin. During the 2008 general election contest, big donors had a somewhat larger role and the $200-or-less donors contributed 24 percent of the campaign’s funds, he said.

Most of the Obama’s 2012 funds will be allocated for television advertising, but campaign officials plan to spend many millions cultivating state-level volunteer networks. The networks are needed to find and motivate potential supporters, to plan placards, check registration lists, register new voters – especially in the Hispanic community – and then deliver them or their votes to the ballot boxes.

The Chicago-based campaign is already underway, and is recruiting volunteers and helping to register voters.

Obama raised $745 million in 2008, when the economy was in better shape, and enthusiasm among Democratic-leaning voters was far higher. Back then, the campaign benefit from roughly 560 “bundlers” who persuaded friends to donate a collective total of $76.5 million to the 2008 campaign, according to the D.C.-based Center for Responsive Politics.

He raised so much money that he declined to accept federal funding, which would have subjected his campaign to spending limits and stricter reporting requirements.