Hillary Clinton supporters and fundraisers are expressing concerns to the Democratic front-runner's campaign that she may be too heavily damaged by her use of a private email server during her time as secretary of state. They also cited concerns about the aura of secrecy that has surrounded her since the server was discovered. In a conference call Wednesday, Clinton's press secretary discussed declining poll results in early nominating states with fundraisers from the Southeast.

Brian Fallon, the secretary, told the group that the campaign was prepared to combat expected attacks in the future. Challenges that are expected include the release of a book entitled "The Clintons' War on Women" that was written by a former Donald Trump consultant and the coming Benghazi hearings in Congress. 

What the campaign can't control, however, could be the most damaging: the monthly release of her emails from her time at the State Department and the ongoing FBI investigation of her use of the email server.

"I’ll be very clear — that issue is going to be with us for the next several months, if only because the emails themselves are on a schedule where they get released every 30 days,” Fallon said, according to a Politico reporter who listened in on the call. “And that will be true until the end of the year. Unfortunately, we can’t control that.”

Those in the call, while appreciative of the briefing, weren't all convinced by the statements. Each of the fundraisers had raised about $27,000 for Clinton.

"Is there a lesson learned? Because there will be five or six more of these between now and then," said Fort Lauderdale, Florida, lawyer Mitchell Berger, who will host a fundraiser for Clinton in October. "There’s no question in my mind that between now and next November there will be new Benghazis and new emails."

Clinton has been the subject of Republican criticism for the Sept. 11, 2012, Benghazi attacks in Libya that resulted in the death of U.S. Ambassador Chris Stevens and three other Americans. Her use of a private email server has been criticized as it reportedly violated stated Obama administration policies to use government servers instead of private accounts.

The former first lady has seen her polling drop sharply over the last two months. She's still in first, but the unlikely rise of U.S. Sen. Bernie Sanders, I-Vt., seems to be exposing her weakness in the field. Clinton had 44.7 percent support in a national average of polls, according to Real Clear Politics, and Sanders received 23.3 percent. She is down from the low-60s in early July.