WASHINGTON (Reuters) - U.S. Democratic presidential candidate Hillary Clinton raised more than $28 million in the last three months, her campaign said on Wednesday, falling short of her nearly $48 million fund-raising haul in the previous quarter.
Campaign aides said 93 percent of the donations were in amounts of $100 or less, which they said was a sign of broad-based grassroots support as Clinton fights off a challenge from the party's liberal wing led by U.S. Senator Bernie Sanders of Vermont.
The fund-raising figure for July through September did not include a breakdown of the total number of donors to Clinton, the average donation, or how many donors have already given the legal maximum for the primary campaign of $2,700.
Sanders raised more than $24 million in the last three months. He has galvanized the party's left-leaning activists and taken advantage of Clinton's declining opinion poll ratings on honesty and trustworthiness to surge into contention.
The Clinton campaign released the preliminary fund-raising numbers, watched closely as an early indicator of a candidate's appeal and staying power, ahead of the Oct. 15 deadline for filing an official report with the Federal Election Commission.
The campaign's fund-raising is only a portion of the donations flooding the presidential race and do not include the money raised by allied Super PACS. Those groups, which are legally not supposed to work in concert with candidates but can advertise on their behalf, report their fund-raising separately.
Clinton remains the front-runner for the Democratic nomination in the November 2016 election, but she has struggled to shake off lingering questions about her use of a private email server while she was secretary of state.
Clinton has apologized for the email practice, but the controversy has dented her support among Democrats and helped bolster Sanders.
Clinton's troubles also have given rise to a possible late entry into the Democratic race by Vice President Joe Biden, who says he is evaluating whether he and his family have the energy and commitment for a presidential race after the recent death of his son Beau.
Clinton led the 2016 Democratic presidential pack in fund-raising in the previous quarter, which ran from April through June. Her campaign raised nearly $48 million and her top allied Super PAC raised a further $15.6 million.
For more on the 2016 presidential race, see the Reuters blog, "Tales from the Trail" (http://blogs.reuters.com/talesfromthetrail/) .