Concerned that it could lose several primaries and caucuses through the rest of February, Senator Hillary Rodham Clinton’s campaign sought to create an alternate storyline of success on Thursday by announcing that Mrs. Clinton had raised $7.5 million online so far this month.
That unusually high figure was quickly overshadowed by Senator Barack Obama’s announcement that he had raised the same amount in 36 hours since the 22-state contest on Tuesday, in addition to the $32 million that he raised in January.
Mrs. Clinton drew $13.5 million in January.
With Tuesday behind them, the rivals have turned some of their ferocity away from voters and toward their donors, seeking the clear-cut victory in fund-raising that neither could secure at the ballot box this week, when Mr. Obama won 13 states and Mrs. Clinton 9.
Mr. Obama’s fund-raising dominance, especially his announcement on Jan. 31 that he had raised $32 million, has sent jitters through Mrs. Clinton’s donor base. Some of her biggest donors grew even more concerned on Wednesday when her advisers said that she had lent the campaign $5 million of her own money and that some senior aides were working this month without salaries.
Several donors and senior aides said they were not aware of the loan until Wednesday.
Mrs. Clinton’s team mobilized Thursday to send reassuring messages to donors and supporters. The campaign first announced raising $4 million in 24 hours, then $6 million in 36 hours and then $7.5 million in total since Feb. 1.
Neither her nor Mr. Obama’s figures could be confirmed because fund-raising reports for this period will be made public in April.
“February is going to be by far our biggest month, by a huge amount,” Terry McAuliffe, Mrs. Clinton’s campaign chairman, said in a conference call on Thursday with 300 donors that the campaign allowed reporters to listen to.
“It’s going to allow us to do everything we needed to do,” Mr. McAuliffe added, noting that the campaign would begin advertisements next week in Ohio and Texas, which hold primaries on March 4 with hundreds of delegates at stake.
Mr. Obama, speaking to reporters, zeroed in on Mrs. Clinton’s loan and said that her decision not to disclose her income tax returns raised questions about the loan.
“I’ll just say that I’ve released my tax returns,” he said, responding to a question about tax returns. “That’s been a policy I’ve maintained consistently. I think the American people deserve to know where you get your income from.”
Mr. Obama stopped short of issuing a call for Mrs. Clinton and former President Bill Clinton to release their returns.
“I’m not going to get into the intricacies of their finances,” Mr. Obama told reporters as he flew to a rally in Nebraska. “That’s something that you’ll have to ask them.”
Nebraska holds nominating caucuses on Saturday.
Clinton campaign officials said she would release her returns if she won the nomination. The officials said there was enough information in her public Senate financial disclosures to assess her personal finances.
Her Senate forms do not list exact deductible expenses like interest or medical costs. The tax returns would show exact interest and dividends from investments, not just the ranges on the disclosure forms.
Mrs. Clinton has been an advocate for transparency in campaign finance, as has Mr. Obama.
For all the confidence expressed by the Clinton campaign, the onus remains on Mrs. Clinton to show fund-raising muscle, in view of her raising less and relying on the loan as well as a $10 million transfer last year from her Senate campaign account to her presidential account.
Advisers said the loan was made on Jan. 28 from Mrs. Clinton’s share of her personal funds that she has with Mr. Clinton. They said it was not a bank loan, nor was collateral needed to secure it. The advisers said no investments were liquidated to make the loan.
The loan was not disclosed widely until after the vote on Tuesday night, Clinton advisers said, for fear that the news might make Mrs. Clinton look like a fading candidate. Several donors said Wednesday that they were concerned that the campaign was essentially running on fumes, especially when they learned that some aides were working without pay. Shortly after midnight Wednesday, however, the Clinton team issued an e-mail message saying that it had raised $3 million in 24 hours. By daylight on Thursday, the advisers said the campaign was so successful that all aides would be paid and that Mrs. Clinton’s war chest seemed to be stabilizing.
The advisers used the conference call in part to focus attention on the Ohio and Texas primaries. The aides say Mrs. Clinton believes she has a better chance in those states than in many of the contests this month like Hawaii, Louisiana, Maryland, Virginia and Washington State.
“I think we’ll have some bumps in the road, some difficult states in the next week or two,” Mark Penn, the senior strategist of the campaign, told the donors.
He and Mr. McAuliffe emphasized the importance of the Ohio and Texas primaries.
Mr. Obama focused Wednesday on the next primaries and his fund-raising. The $32 million in January, aides said, came from 275,000 people who gave $100 or less. Ninety percent of the money came from online donations.
The disparity between his contributions and Mrs. Clinton’s, he said, demonstrate a gap in enthusiasm.
“I think there’s no doubt that she has not generated the kind of grass-roots enthusiasm that we have,” Mr. Obama said. “It’s not for lack of trying. She’s got a former president actively fund raising for her, as well as people like Terry McAuliffe. But what we’ve done is created this base where people send $25 checks, $50 checks on an ongoing basis.”
Kitty Bennett contributed reporting.