Fundraiser in chief: Hillary Clinton. Credit:The New York Times At the time, donors to the former Florida governor pushing the limits of campaign-finance rules. The stockpiling of seven-figure cheques before Bush even declared candidacy spurred a flurry of anxious conversations between Clinton and her staff, according to hacked emails posted by WikiLeaks. But the former secretary of state had her own financial weapon: a network of political backers that she and her husband, former president Bill Clinton, had methodically cultivated over 40 years. Determined not to fall behind in the money race, Hillary Clinton ramped up her appeals to rich donors and shrugged off restrictions that President Barack Obama had imposed on his fundraising team. Even as her advisers fretted about the perception that she was too cozy with wealthy interests, they agreed to let lobbyists bundle cheques for her campaign, including those representing some foreign governments, the emails show.

Hillary Clinton on the campaign trail with vice-presidential candidate Tim Kaine. Credit:AP Top aides wooed major donors for super PACs, taking advantage of the leeway that campaigns have to legally collaborate with the groups on fundraising. The effort paid off. Together with the party and pro-Clinton super PACs, the Democratic nominee had amassed $US1.14 billion to support her campaign by the end of September – on par with what Obama and his allies brought in for his 2012 re-election bid. In comparison, Republican nominee Donald Trump, who did not begin fundraising in earnest until the end of May, had collected $US712 million, including $US56 million of his own money. Hillary Clinton speaks during a campaign event in Columbus, Ohio earlier this year. Credit:New York Times Unlike Obama, Clinton fully embraced super PACs from the very beginning of her race, helping pull in larger cheques from donors than the president did.

An analysis by The Washington Post found that more than a fifth of the $US1 billion donated to help her bid was given by just 100 wealthy individuals and labour unions – many with a long history of contributing to the Clintons. Chelsea Clinton, pictured here at campaign rally, works for the Clinton Foundation, which has seen Hillary Clinton embroiled in controversy over conflict of interest claims. Credit:AP The top five donors together contributed one out of every $US17 for her 2016 run: hedge fund manager S. Donald Sussman; Chicago venture capitalist J.B. Pritzker and his wife, M.K. ($US16.7 million); Univision chairman Haim Saban and his wife, Cheryl ($US11.9 million); hedge fund titan George Soros ($US9.9 million); and SlimFast founder S. Daniel Abraham ($US9.7 million). Since modern-day campaign finance rules were put in place in the 1970s in the wake of the Watergate scandal, no president has ever been elected with the help of wealthy contributors who doled out such huge sums. The possibilities changed with the 2010 advent of super PACs, which can accept unlimited sums from individuals and corporations. Sussman, Clinton's top backer, said his top priority is dismantling the big-money system that has flourished in the wake of the Supreme Court's Citizens United v. Federal Election Commission decision.

"It's very odd to be giving millions when your objective is to actually get the money out of politics," Sussman said. "I am a very strong supporter of publicly financed campaigns, and I think the only way to accomplish that is to get someone like Secretary Clinton, who is committed to cleaning up the unfortunate disaster created by the activist court in Citizens United." Clinton has emerged as both one of the sharpest critics and biggest beneficiaries of the new campaign-finance landscape. On the campaign trail, she has repeatedly called for an overhaul of how elections are financed and vowed to overturn the Citizens United ruling, which allowed corporations to spend money on independent political activity. She has also pledged to sign an executive order requiring federal contractors to disclose political spending and to create a matching system for small donors in federal races. "More than 2.6 million Americans have donated to this campaign because they know Hillary Clinton is the best candidate to bring us toward a more inclusive society with an economy that works for everyone, not just those at the top," said spokesman Josh Schwerin. But Clinton would also enter the White House deeply indebted to a group of elite donors who have backed her and her husband for decades – helping raise $US4 billion for their political and philanthropic causes over the years.

Top allies have financed not only their political causes, but their legal needs and their philanthropy. About half of the money they have raised – more than $US2 billion – went to the Clinton Foundation, which has financed access to HIV treatments around the world, promoted early literacy programs and trained African farmers on improving their crop yields. The foundation's fundraising has also generated controversy in this year's campaign, as critics have seized upon its acceptance of money from foreign governments while Hillary Clinton was secretary of state. Separately, donors gave $US888 million to support Bill Clinton's two presidential runs, Hillary Clinton's two Senate campaigns and her 2008 presidential bid, according to campaign-finance records. As she ramped up her 2016 bid, Clinton's advisers worried that her call for a constitutional amendment to overturn Citizens United – a long-shot policy goal – would not be enough to combat the view that she was closely aligned with wealthy interests. In a May 2015, discussion about possible campaign finance proposals Clinton could endorse, Dan Schwerin, director of speechwriting, wrote that he was concerned about "complaints of hypocrisy."

"Policy alone won't make the cognitive dissonance go away, in fact it might heighten it," he added. "But having her make the unilateral disarmament argument directly and maybe even some straight talk that cuts to the core of people's concerns about her relationship with donors in general, might help." At the same time, her campaign was contending with a new reality: the political world had changed since Clinton's last run for office. Super PACs were now central players in campaigns and many of her GOP rivals, including Bush and Wisconsin Governor Scott Walker, were pushing the bounds of the use of such groups. The Republicans' aggressiveness – and the lack of response from regulators – alarmed Clinton. In early May 2015, she forwarded her advisers an article about the lack of enforcement by the polarised Federal Election Commission, which is charged with policing election rules. "What do you suggest we do?" she asked. "I have no magic solutions other than execution," responded campaign chairman John Podesta, adding that the campaign needed to expand its network of fundraisers who bundle cheques and "get Priorities functional," a reference to Priorities USA Action, the main super PAC backing Clinton.

"We should also ask BHO to do more in light of this, although they are kind of prissy about how they approach this," he added, referring to Obama. Mook agreed: "I think we focus hard on raising as much as we can and then throw the kitchen sink at everyone who we believe steps over the line, understanding that has limited impact." The relevance of hacked emails The Clinton campaign has refused to confirm the authenticity of the emails posted by WikiLeaks, which were allegedly hacked from Podesta's personal account. US government officials have already caused Russia of attempting to interfere in the US election, including through a previous hack of the Democratic National Committee, and are investigating whether Russian intelligence services are behind the Podesta hack.

The emails show that Clinton decided to step up her own fundraising schedule that spring even if, as Adebin noted at one point, it made the schedule "a little crazy." And she decided to forgo some of the self-imposed limitations that Obama had put on his own fundraising. The campaign decided to not only let lobbyists bundle cheques, but, after extensive internal debate, permitted some of those registered as representing foreign governments to raise money as well. Mook explained to other top advisers that the campaign's outside attorney, Marc Elias, "made a convincing case to me this am that these sorts of restrictions don't really get you anything ... that Obama actually got judged MORE harshly as a result," he wrote. "He convinced me. So ... in a complete U-turn, I'm OK just taking the money and dealing with any attacks. Are you guys OK with that?" Communications director Jennifer Palmieri responded: "Take the money!!"

Clinton and her aides also sent clear signals early on that they wanted supporters to back Priorities USA, which had originally formed to support Obama's re-election despite his objections to super PACs. In an April 2015 memo, Elias laid out the ways that super PACs and the campaign could legally interact, noting that the campaign could share the names of prospective donors with Priorities – including how much they might be willing to give. Campaign officials could not explicitly tell the super PAC how much to ask for, he stressed. But they could say something like, "Donor A works in financial services and has been a long-time contributor. I think she'd be willing to do six figures for Priorities," he wrote. Clinton also got a boost from another super PAC, Correct the Record, led by her ally David Brock, which coordinates directly with the campaign on opposition research, taking advantage of an exemption designed for bloggers. To donors, the different groups were often presented as pieces of a unified enterprise.

Four days before Clinton officially jumped in the race, retired banker Herb Sandler got an email from a Washington fundraiser working for Priorities USA Action who introduced himself as "the Finance Director for Hillary Clinton's superpac," according a message Sandler forwarded to Podesta. Two months later, Sandler gave Priorities $US1 million. Podesta was recruited to pitch major donors to support both the campaign and Priorities as he travelled around the country, the emails show. The emails also show that Clinton's aides were intensely focused on locking up the support of labor unions – a source of cash and ground troops – and often agonised over how to keep them on board amid competing political interests. In April 2015, after attending a gathering of major liberal donors, senior policy adviser Ann O'Leary noted that "a number of our friends" – including the Service Employees International Union – wanted Clinton to back organised labor's "Fight for 15" campaign to raise the minimum wage. "Can we do something creative to support efforts without coming out for a number?" she asked.

Two months later, Clinton garnered huge cheers when she called in to a convention of fast-food workers, telling them "thank you for marching in the streets to get that living wage" – stopping short of endorsing a specific figure for the minimum wage. SEIU President Mary Kay Henry dashed off a note to Podesta with the subject line, "It worked!" "I looked around the stage and most fast food leaders had tears streaming down their face," she wrote, adding that the sentiment in the room was, "She's on our side." "Amazing," responded Abedin when a staffer forwarded her the note. "Hope you shared with HRC!" SEIU officials said Henry's email was referring to the support Clinton has shown for working families on a variety of issues, adding that members of the union have felt even more energised by her candidacy as the election has drawn closer.

Loading In the fall of 2015, the SEIU endorsed Clinton, who has since expressed support for a $US15 minimum wage. The union donated $US1 million to Priorities and is now spending tens of millions on an independent field effort to turn out voters in battleground states. The Washington Post