Bush donors giving for the first time in the 2008 presidential election represent about 9% of Sen. McCain's total receipts in the first two months of the year.
"We wanted to see what shook out of the race," said Charles Mussallem of Jacksonville, Fla., a Bush 2004 donor who gave the $2,300 maximum allowed donation to Sen. McCain in January, as did his brother. "The good money was not bet on him initially."
Mr. Mussallem owns art galleries in Florida and Arizona that sell oriental rugs and decorative objects, and he and his brother know Sen. McCain personally. "We told him if he got out of New Hampshire, we would look at supporting him," Mr. Mussallem said. "He did."
Sen. McCain also lags far behind his Democratic rivals in total funds raised as Democrats eager to take back the White House have been turning out in much higher numbers than Republicans to vote in this year's primary elections.
From the start of his campaign through the end of February, the Arizona senator had raised $63 million for the primary election, and at the end of February had only $4.5 million left in the bank. He also reported large debts that his campaign says were mostly settled in March after he repaid a $4 million bank loan.
By comparison, Sen. Obama had raised $190 million through February for his primary bid, much of it through the Internet. Sen. Clinton had raised nearly $152 million through February for the primary, including her $5 million personal loan to her campaign.
Sen. McCain is beginning to get support from former Republican rivals in addition to former New York Mayor Rudy Giuliani, who dropped out of the race on Jan. 30.
Supporters of former Massachusetts Gov. Mitt Romney gave Sen. McCain $620,000 in February and $317,000 in January, before it was clear that Mr. Romney wouldn't win. Backers of ex-Sen. Fred Thompson of Tennessee gave Sen. McCain $354,000 in February and $138,000 in January, the analysis shows. Mr. Thompson left the race on Jan. 22.
Mr. Romney, who has said publicly that he would be interested in becoming Mr. McCain's vice president since dropping out Feb. 7, has had less time to swing his network behind Sen. McCain, though he has said he will do so.
The money Sen. McCain is raising now will mostly be used to finance his campaign through the summer, up until the Republican nominating convention in September. Some questions remain about whether Sen. McCain can legally withdraw from a public financing program for his campaign and continue to spend money over the summer above limits imposed by the public system.
Sen. McCain is in the tricky position of trying to avoid the fate of his former Senate colleague and the 1996 Republican nominee, Bob Dole of Kansas.
Sen. Dole nearly fell "off the public radar screen because he didn't have the resources to maintain a robust campaign" in the summer of 1996, and he lost to Bill Clinton, said Washington lobbyist Dirk Van Dongen, a former Giuliani fund raiser who is now backing Sen. McCain.
Write to Mary Jacoby at firstname.lastname@example.org