Under rules of public financing, a candidate has access to $85 million from a taxpayer-financed fund for the general election, a substantial amount to spend for the roughly two months after this year’s conventions. But this election cycle has shattered fund-raising and spending records and upended expectations.
The setting, which has the feel of an Internet start-up, is emblematic of how Mr. Obama, of Illinois, has been able to raise so much money.
Mrs. Clinton’s operation has also been pushing to improve its efforts online, with her campaign saying Tuesday that it brought in $15 million over the Internet in February, with donations jumping after news broke that she had lent $5 million to her campaign.
“I know you just made a donation, but we are about to enter the most decisive period of the campaign,” he said, signing his name at the end, “Thank you, Barack.”