A 2003 book by liberal Massachusetts Sen. [crscore]Elizabeth Warren[/crscore] undermines a claim that Hillary Clinton made Sunday about her support for a 2001 bankruptcy bill that helped credit card companies and other creditors.

In an interview with CNN’s Jake Tapper, Clinton, who was elected to the Senate from New York in 2000, said she changed her vote on a bankruptcy bill she opposed as first lady because it included new provisions that would protect single mothers’ ability to collect child support from ex-husbands who declare bankruptcy.

“I was deluged by women’s groups and children’s groups because the version of the bill that was going to be voted on did not protect child support, did not protect vulnerable women and their children from what would happen to them if their partner, their spouse went into bankruptcy and was able to discharge those obligations,” Clinton said Sunday.

But in the endnotes to her 2003 book, “The Two-Income Trap: Why Middle-Class Parents Are Going Broke,” Warren paints an entirely different picture.

The populist champion — who holds enormous sway in the progressive wing of the Democratic party — wrote that women’s groups and consumer advocacy groups were not pushing the provision that Clinton used in defense of her Senate vote flip-flop. She also asserted that the new provision did little to protect single mothers.

Warren’s endnotes point to a 2001 Clinton press release which “cited a provision that moved child support claims higher in the distribution pecking order in bankruptcy, by permitting single mothers to stand first in line for distributions from the liquidation of an ex-husband’s assets.”

But Warren disputed that claim.

“While this amendment may have provided some political cover, it offers virtually no financial help to single mothers, since the overwhelming majority of ex-husbands don’t pay anything distributions during bankruptcy,” the endnotes read.

“Of far more importance was the fact that the bill would permit credit card companies to compete with women after bankruptcy for their ex-husbands’ limited income, and this provision remained unchanged in the 1998 and 2001 versions of the bill. Senator Clinton claimed that the bill improved circumstances for single mothers, but her view was not shared by any women’s groups or consumer groups.”

Clinton’s vote on the 2001 bankruptcy bill — which did not pass, despite Clinton’s support — became a hot political issue earlier this week after the Democratic front-runner pushed back against accusations that she is beholden to Wall Street and other financial services firms. The industry has contributed millions of dollars to her campaigns and paid her and husband Bill Clinton millions of dollars in speaking fees.

“Anybody who knows me who thinks that they can influence me — name anything that they’ve influenced me on,” Clinton said during a CNN town hall on Wednesday.

And during a debate on Thursday, Clinton lashed out at her Democratic opponent, Vermont Sen. Bernie Sanders, accusing him of running a negative campaign and using “artful smear(s)” against her.

While Sanders — who voted against the 2001 bankruptcy bill as a Congressman — did not directly confront about her flip-flop, his campaign sent emails out Thursday pointing to Warren’s critique.

Particularly damning for Clinton is a video from an interview that Warren gave to Bill Moyers in 2004 in which she summarized Clinton’s transition from an opponent of the bankruptcy bill to a supporter.

Warren said that she met with then-first lady Clinton to review a bankruptcy bill that would soon pass the House and Senate and would take bankruptcy protections away from consumers. She praised Clinton for her response to the meeting and credited her with changing the White House’s position on the bill. Then-President Bill Clinton declined to sign the bill into law.

But after Hillary Clinton left the White House for the Senate chamber, her position changed, Warren lamented.

“One of the first bills that came up after she was Senator Clinton was the bankruptcy bill,” Warren told Moyers, noting that: “She voted in favor of it.”

Asked why Clinton might have switched her position, Warren paused and said that, “as Senator Clinton the pressures are very different.”

“It’s a well-financed industry,” she said, referring to the financial services business.

Warren offered a similar analysis in her 2003 book.

[dcquiz]”Had the bill been transformed to get rid of all those awful provisions that had so concerned First Lady Hillary Clinton? No,” Warren wrote. “The bill was essentially the same, but Hillary Rodham Clinton was not.”

She wrote that while Clinton had been “willing to fight for her beliefs” as first lady, “as New York’s newest senator, however, it seems that Hillary Clinton could not afford such a principled position.”

In defending her 2001 vote on Sunday, Clinton portrayed herself as a lone warrior who was forced to compromise in order to help single mothers.

“I didn’t like the bill any more than I had liked it before. It still had very bad provision. But I also pushed hard for a deal to protect women and children. So OK, I held my nose. I voted for it. It never became law,” she told Tapper.

She then repeated her accusation that Sanders is using “artful smear(s)” against her.

WATCH:

Follow Chuck on Twitter