'Clinton Cash' takes aim at Hillary. Will it hurt her 2016 campaign?

The New York Times call it the "most anticipated and feared book of a presidential cycle."

The Daily Mail hails it as "the bombshell book that could derail Hillary's campaign."

And the right-leaning Breitbart says it "could be a presidential game-changer."

“Clinton Cash: The Untold Story of How and Why Foreign Governments and Businesses Helped Make Bill and Hillary Rich,” by Peter Schweizer, is the latest salvo aimed at Hillary Rodham Clinton's nascent campaign, and according to reports, it may be damaging.

Due to hit shelves May 5, the book is a 186-page investigation of foreign donations to the Clinton Foundation, the culmination of a one-year investigation by Mr. Schweizer, a former speech-writing consultant to President George W. Bush. 

His claim: foreign governments and organizations that donated to the Clinton Foundation, and to the Clintons themselves in speaking fees, received favors in exchange from the State Department, headed by then-Secretary of State Hillary Clinton. That's according to reporting by The New York Times, which was given an advance copy of the book and ran an excerpt on it Sunday.

“We will see a pattern of financial transactions involving the Clintons that occurred contemporaneous with favorable U.S. policy decisions benefiting those providing the funds,” Schweizer writes in his introduction.

The favors he outlines include free-trade agreements and development projects granted to nations in exchange for payments to the Clinton Foundation or to Bill Clinton in speaking fees.

Schweizer's "examples include a free-trade agreement in Colombia that benefited a major foundation donor's natural resource investments in the South American nation, development projects in the aftermath of the Haitian earthquake in 2010, and more than $1 million in payments to Mr. Clinton by a Canadian bank and major shareholder in the Keystone XL oil pipeline around the time the project was being debated in the State Department," the New York Times writes.

"I think there are things that went on at the Clinton Foundation that are going to shock people," Republican Rand Paul, a member of the Senate Foreign Relations Committee which received a briefing on the book, and who is also running for his party's nomination, told Fox News. "And I think they're going to make people question whether or not she ought to run for president." 

It's clear that the Clintons, at least, have taken notice.

The Clinton Foundation recently stopped accepting money from all but six foreign governments, and Hillary resigned from foundation's board when she announced her candidacy.

Her campaign is also gearing up to answer to the book's claims.

“The newly assembled Clinton campaign team is planning a full-court press to diminish the book as yet another conservative hit job,” reports the Times.

A campaign spokesman, Brian Fallon, told the Times the book is part of a coordinated Republican attack on Clinton that is “twisting previously known facts into absurd conspiracy theories." "It will not be the first work of partisan-fueled fiction about the Clintons’ record, and we know it will not be the last," he said.

Will "Clinton Cash," as Rep. Paul suggested, really hurt Hillary, or will it go down as just another right-wing, anti-Clinton conspiracy?

For starters, it should be noted that the book hasn't yet hit shelves, so it's unclear whether Schweizer can prove that there is a direct link between Clinton Foundation donations and State Department actions. If he can, it would be extremely damaging to Clinton.

Even without knowing whether there is a direct link, however, the book, at first glance, may hurt Hillary's 2016 campaign.

In light of her recent "e-mail-gate" scandal (where she used a private e-mail server to conduct correspondence while at the State Department, then deleted some of the e-mails she said were "personal"), the revelations in the book may lead voters to believe Clinton has something to hide.

It may also dent her image as a champion for everyday Americans. From 2001 to 2012, the Clintons’ total income was at least $136.5 million, Schweizer writes, echoing earlier reporting by the Washington Post. That may tarnish the Clinton campaign's effort to paint their candidate as a Chipotle-scarfing, roadtripping kind of gal.

What's also troubling for Clinton is that this story isn't likely go away anytime soon. Major news organizations including The New York Times, The Washington Post, and Fox News "have exclusive agreements with the author to pursue the story lines found in the book," reports the New York Times.

Of course, it is possible that the book's claims have been over-hyped and that the Clinton campaign's efforts will convince voters to dismiss the attacks.

After all, there have been other books that the Clinton camp has successfully swatted away, including Edward Klein’s “Blood Feud,” and Daniel Halper’s “Clinton Inc.: The Audacious Rebuilding of a Political Machine.”

And, as Buzzfeed's Ben Smith pointed out on Twitter, the book's claim – that Foundation donations directly translated into favors – is very difficult to prove.

But, as CNBC pointed out, even if Schweizer can't prove it, it may still damage Clinton.

"Correlation is not causation," Politico's Ben White wrote for CNBC. "But in politics it can still be damaging."