In an analysis of public records and Clinton Foundation data, The Washington Post found that there was an overlap of Bill and Hillary Clinton's charitable work and their growing personal wealth. The Post's Rosalind S. Helderman breaks it down. (Alice Li/The Washington Post)

The massive fundraising and wealth-generating operation that Bill and Hillary Rodham Clinton have built over the past decade and a half has revived one of the most enduring criticisms of the couple: that they have a blind spot when it comes to setting ethical boundaries with the people who give them money.

Two factors could make the current questions even more problematic. First, the Clintons now bring in contributions on a scale that would have been unimaginable during the controversies that beset Bill Clinton’s presidency in the 1990s.

Second, many of those who have funded their charity and their campaigns have also had a role in elevating the couple — whom Hillary Clinton once described as “dead broke” when her husband left office — into the ranks of the super-rich.

A Washington Post analysis found that the former president was paid at least $26 million in speaking fees by companies and organizations that also donated to his foundation — a quarter of his overall speaking income between 2001 and 2013.

While it is far from unusual for an ex-president to burnish his legacy with charitable works or to fill his family bank account by giving six-figure speeches, no one else has done so while his wife was serving as secretary of state and building the machinery for her own White House bid.

Complicating the issue further is the fact that many of the large donations to the Clinton Foundation and most of Bill Clinton’s speaking fees have come from foreign sources — a practice that continues.

“The story line of the Clintons’ fundraising goes way back, and it hasn’t always been flattering,” said Viveca Novak, communications director for the Center for Responsive Politics. “It wouldn’t have been hard to predict that the foundation’s acceptance of huge tranches of foreign money would raise questions about whether those donors would get favorable treatment if Hillary Clinton wins the White House.”

The New York Times on Thursday added new evidence that this practice creates, at a minimum, perceptions of conflict.

A Canadian mining executive, Ian Telfer, who donated heavily to the Clinton Foundation led a uranium mining company that was sold to the Russians, benefiting from a deal that had to be approved by Hillary Clinton’s State Department. A second executive, Frank Giustra, a major foundation donor, sealed a deal to buy uranium from Kazakhstan in 2005 shortly after a visit to that country with Bill Clinton.

Meanwhile, Hillary Clinton’s campaign is making a preemptive strike on an upcoming book, “Clinton Cash,” by conservative author Peter Schweizer that examines the foundation’s financing and the Clinton family’s wealth. The book provided part of the basis for the Times’ report.

On Thursday, Hillary Clinton’s campaign issued a statement dismissing the report and the book as “innuendo.” Campaign spokesman Brian Fallon said there was no evidence that Clinton’s State Department approved the Russian uranium deal to benefit foundation donors. He said that Clinton was not personally involved in the interagency approval process, that the deal was approved by a variety of government agencies and that the donors involved have said they received no assistance from Clinton in the matter.

In a memo earlier Thursday to allies and surrogates, Fallon wrote: “Republicans, their allies, and the people desperately trying to tear down Hillary Clinton will continue to rely on this book’s false attacks and conspiracy theories, but bit by bit, the truth will come to light. This isn’t the first baseless smear against Hillary Clinton, and it certainly won’t be the last.”

Nonpartisan advocates of limiting money in politics say the problem is, in no small measure, one of the Clintons’ own making. “It would be in everyone’s best interest if the Clinton Foundation adopted a policy of accepting no money whatsoever from any foreign countries, foreign corporations and foreign individuals,” said Fred Wertheimer, a veteran of the fights over campaign finance who is now president of the watchdog group Democracy 21.

There is indeed an echo of the furor that was generated in the 1990s when the Clintons wooed big Democratic Party donors with overnight sleepovers in the Lincoln Bedroom and intimate coffees in the Map Room, where they could rub elbows with the government officials who regulated their industries.

During the 1996 reelection campaign, Vice President Al Gore was dispatched to raise money at a Buddhist temple and dialed for contributions from his phone at the White House. All of that continued to haunt Gore during his own campaign for president.

And in one of his final acts in office, Bill Clinton pardoned fugitive financier Marc Rich, whose ex-wife, songwriter Denise Rich, gave a $450,000 donation to the Clinton presidential library.

That none of this appears to have been illegal was the biggest scandal of all, in the view of campaign finance reform advocates.

The controversies of the 1990s paved the way for passage of the Bipartisan Campaign Reform Act of 2002 — also known as the ­McCain-Feingold Act for its sponsors, Sen. John McCain (R-Ariz.) and then-Sen. Russell Feingold (D-Wis.). A key feature of the law was a ban on the unregulated “soft money” that the Clinton White House had been so adept at raising with its many overtures to deep-pocketed donors.

Shortly after the law passed, as regulations were being drafted to clarify and tighten it, then-Sen. Hillary Clinton (N.Y.) engaged in a heated exchange with Feingold during a private caucus of Senate Democrats. Clinton “acidly” told Feingold “that he did not live in the ‘real world’ of prosecutors ready to catch politicians on technicalities,” the New York Times wrote in an editorial at the time.

Feingold reportedly replied, “I also live in the real world, Senator, and I function quite well in it.”

Now that she is running for president, Clinton has identified campaign finance reform as one of four “pillars” of her campaign.

“We need to fix our dysfunctional political system and get unaccountable money out of it once and for all, even if it takes a constitutional amendment,” Clinton said on her inaugural swing through Iowa after announcing her candidacy.

Tom Hamburger and Rosalind S. Helderman contributed to this report.