Clinton told reporters at her campaign headquarters in Arlington, Va., that she made the loan, adding, "I believe the campaign would have a great month fundraising in January. We intended to be competitive and we were."
Obama, riding a wave of fundraising both from large donors and small Internet contributors, collected a stunning $32 million in January. Clinton campaign chairman Terry McAuliffe said the Clinton campaign raised only $13.5 million for the month. The $5 million was in addition to that amount, Wolfson said.
On Wednesday, the Clinton campaign set a new goal of raising $3 million over the next three days through the Internet.
"We have had one of our best fundraising efforts ever on the Web today and our Super Tuesday victories will only help in bringing more support for her candidacy," said Clinton campaign spokesman Howard Wolfson.
In a teleconference with reporters, Clinton chief strategist Mark Penn said: "We will have funds to compete," he said, "but we're likely to be outspent again."
Hillary and Bill Clintons' financial disclosures, which reveal only broad ranges of assets, place their wealth between $10 million to $50 million.
Clinton's name recognition and lead in polls in some of the bigger upcoming states give her an advantage and Obama's higher spending rate did not translate into victories in several states Tuesday.
But the terrain ahead features contests in the short term that are favorable to Obama. On Saturday, Obama and Clinton will compete in contests in Louisiana, Nebraska and Washington. On Tuesday, Virginia, Maryland and the District of Columbia hold primaries.
The Clinton camp is counting on March 4 matchups in Ohio and Texas and an April 22 primary in Pennsylvania. All three are expensive states in which to campaign.
Obama's camp signaled that he was ready to invest money in those states as well. "We think we're in strong financial position so if we choose to do so in the later states we'll have the ability to do that," campaign manager David Plouffe told reporters Wednesday.
Clinton spent $15 million in December going into the Iowa caucuses and the New Hampshire primary. Her campaign spent at least $9 million in the last two weeks of January advertising in Super Tuesday states. Obama spent about $11 million in Super Tuesday advertising.
Clinton raised $23.7 million in the last quarter of 2007 for the primary elections compared to Obama's $22 million. Both had about $18.5 million cash on hand for the primaries going into January. But Obama roared to a fundraising lead in January by collecting money at the rate of at least $1 million a day and attracting more than 170,000 new donors.
Obama also has a money advantage because he has raised more money from small donations than Clinton. An analysis by the Campaign Finance Institute, which tracks trends in political money, found that Obama raised about a third of his money in 2007 from donors who gave $200 or less. Only one-third of his money came from donors who have given the legal maximum of $2,300, compared to Clinton who raised about half of her money from "maxed out" donors and only 14 percent from donors of $200 or less.