And they say, by a huge margin, that Hillary Clinton did favors for its donors during her time as secretary of state.
A Washington Post-ABC News poll last week showed that about 6 in 10 Americans — 59 percent — think Hillary Clinton's State Department did "special favors" for Clinton Foundation donors. And 90 percent of them think the favors were "inappropriate."
Among those who think special favors were done are 33 percent of Democrats and 62 percent of independents. Even 32 percent of people who say they are voting for Clinton say they believe it.
The same poll showed that 57 percent overall and 32 percent of Clinton supporters said they are concerned about potential conflicts of interest between the foundation's work and her potential presidency.
Emails released from Clinton's time as secretary of state in recent months have shown that a top foundation aide discussed employment for another foundation aide with the State Department. In another case, the same top foundation aide, Doug Band, sought a contact in Lebanon for a top donor. In a third instance, he sought help from longtime Hillary Clinton confidante Huma Abedin to obtain a diplomatic passport. Clinton allies have said that those actions were the sort that a secretary of state's office would typically have engaged in, even if the people had had no connection to the foundation.
The Associated Press found last month that more than half of private individuals who met with Hillary Clinton during her tenure as secretary of state were Clinton Foundation donors — a number that the Clintons have argued lacks context, given how many donors the foundation has and how reputable and non-controversial many of them are.
The Clintons have sought to allay concerns by announcing last month that the foundation will no longer take foreign and corporate money if Hillary Clinton is elected, and that Bill Clinton will step down from the foundation's board and cease fundraising efforts for it if his wife is elected.
The couple's daughter, Chelsea Clinton, will remain involved. Bill Clinton on Tuesday dismissed concerns about her acting as a conduit for donors seeking influence in a new Clinton administration as "bull."
Bill Clinton has made a round of media appearances this week defending the foundation and making the case that the controversy is overblown. He has spoken with CBS, NPR and CNBC in advance of this week's Clinton Global Initiative to press the case and help the Clinton campaign move beyond it.
But there are signs that won't be so easy. The New York Times editorial board has called on the Clintons to go even further in separating themselves from possible conflicts of interest, saying the foundation should stop accepting corporate donations starting now — not just if Hillary Clinton is elected. It also said Chelsea Clinton should end her involvement if her mother wins in November.
"The Clinton Foundation has become a symbol of the Clintons’ laudable ambitions, but also of their tangled alliances and operational opacity," the Times wrote. "If Mrs. Clinton wins, it could prove a target for her political adversaries. Achieving true distance from the foundation is not only necessary to ensure its effectiveness, it is an ethical imperative for Mrs. Clinton."
Bill Clinton will certainly try to make the case Wednesday that the Clinton Foundation and its offshoots have done good work, and few people would dispute that. But as the Times editorial states, it also has become a vehicle for suspicions about backroom dealing and currying favor — feeding and reinforcing a narrative about the Clintons that has long dogged Hillary Clinton's 2016 campaign. And in the minds of a strong majority of Americans, the Clintons clearly haven't put those questions to rest.