Phil Smith* - @piripismith
Opinion -Hillary Clinton remains under attack over her email server and the Clinton Foundation. Phil Smith explores the anatomy of negative campaigning.
Negative campaigning is not inherently bad. It is reasonable to question an opponent's character, or point out where policy differs from practice.
But it's popular because it's effective. It doesn't even have to be accurate, it just has to align with existing biases, or excuse them.
For an insight into negative campaigns, consider the 2004 US presidential race between John Kerry and George Bush.
A group calling itself Swift Boat Veterans for Truth ran a smear campaign against John Kerry. The evil genius of the attack was that it scuttled Mr Kerry's key asset - that he was a thrice-decorated naval war hero.
He was portrayed instead as reckless, lying - even cowardly - and an enemy of serving men and women. George W. Bush had himself avoided any active military service, and the Swift Boat claims were discredited - but the smear still worked.
It worked because it wasn't about the facts; it was about class prejudice.
Mr Kerry was obviously a member of the north-eastern liberal elite. He was an educated rich ponce and he sounded like it. He was 'one of them'.
Mr Bush was also from an elite family, but he was southern and folksy and - you might say - less obviously educated. He was 'one of us'.
When the rich ponce gets a medal, average Joes have a sneaking suspicion that he probably didn't deserve it.
It's an easy task to make a slur stick - confirmation bias does the job for you. The trick is not to change potential voter's minds, it's to provide excuses for them to vote in line with their prejudices.
Many attacks against President Barack Obama were ludicrous, but they didn't need to be strong. They only needed to provide closet racists with an excuse for voting against him, so they could say to themselves "I'm not a bigot, it's because...".
Which brings us to the current election. There have been three main prongs to the attacks on Democrat presidential nominee Hillary Clinton's character: the Benghazi attack, the email server, and the Clinton Foundation.
There were eight congressional investigations into the Benghazi incident. The most recent spent over two years trying to pin blame on the former Secretary. They failed, but succeeded in sowing doubt over Mrs Clinton's competence and honesty.
The email server has been a particularly effective attack despite being flimsy. Private email servers were used by the two Secretaries of State prior to Clinton and the one after her. Their servers also held classified material. Her server wasn't hacked (that we know of), but the Department of State's server has been.
But none of that matters. The important thing is painting it as reckless and evidence that she has 'something to hide'.
Recent attacks have focused on the Clinton Foundation. Republican presidential candidate Donald Trump has called it "the most corrupt enterprise in political history", a feat which would take some achieving.
The Foundation is a charity Mrs Clinton's husband Bill Clinton started after his presidency, and focuses on health, education, climate change and disasters both in the US and internationally.
Charity Watch gave the foundation their highest rating, so it's not poorly managed. The main accusation is that foreign donors to the charity may have asked for meetings and hoped for favours from Mrs Clinton when she was Secretary of State. They may have. Meetings with political donors are commonplace. So are favours. For example, US ambassadors to New Zealand are usually donors to the sitting president's campaign.
There's no evidence of favours. There is evidence of them being declined, even when the Foundation needed the favour. Insinuations without evidence neatly fuel the narrative that Mrs Clinton is dodgy.
Ironically, among the donors to this "criminal" foundation is a certain Donald J. Trump. And, deepening the irony, the Trump Foundation made a political donation to Florida State Attorney-General Pam Bondi, who was weighing up a fraud case regarding Trump University. She opted against prosecution. This story has gained less traction, possibly because it doesn't seem surprising.
The three lines of attack against Mrs Clinton are cleverly aimed to undermine two of her strongest defining attributes: her charitable work and her time as Secretary of State. They don't have to be proven, they only need to be difficult to disprove.
As attacks, they are more effective than the long-standing conspiracy theory that the Clintons have assassinated scores of political enemies. That may excite the true believer but it won't convince a wavering voter.
The aim is sowing doubt, reinforcing biases, and excusing them. This is especially effective because Mrs Clinton has a crippling underlying weakness in the minds of many voters - she is a woman.
There is a group of people so viscerally opposed to the idea of a black president they can't even believe Mr Obama is American. Equally, there are voters who would never admit that they are horrified by strong women and appalled at the prospect of a female president. They oppose Hillary Clinton but need an excuse that is not about gender. That reason has become too embarrassing.
*Phil Smith is an award-winning journalist who has reported for RNZ from China, India and Australia. He has spent far too long revelling in the byzantine minutiae of American politics.