One Comey catastrophe
When FBI Director James Comey sent a letter to lawmakers on October 28 local time announcing a probe into emails possibly connected to the long-running Clinton case, he threw an 11th-hour grenade into the campaign.
The probe into Hillary Clinton's use of a private email server while Secretary of State was supposedly put to bed by Comey in early July when he called it "extremely careless" but insufficient for a criminal case.
Statistician Sam Wang estimates that Clinton - less than two weeks from election day - dropped 4 per cent in national polling immediately after the Comey letter. She recovered slightly days later. Statistician Nate Silver believes the Comey hit was about 3 per cent against Clinton. Vox says that across 14 battleground states, Trump gained an average of 2.4 points after October 28.
Politico reporter Glenn Thrush wrote that both campaigns believed it was a game changer.
NBC political editor Mark Murray tweeted that the race wasn't close on October 27 but became close enough for Trump to pull off his Electoral College win.
As Vox reported, it hit Clinton at the very worst time as undecided voters were making up their minds. It gave Republicans lukewarm about Trump an excuse to return home. It reminded others why they disliked Clinton in the first place. Polling data showed that voters who decided late largely went for Trump.
Comey is now being investigated at the Justice Department.
A second catastrophe
It has emerged that Comey effectively sat on what information the FBI knew about Russia's alleged attempts to influence the election and the Trump camp's reported ties to Russia.
The Guardian reported that the FBI sought a wiretap on four members of Trump's team, because of the alleged contacts. The BBC reported that "a joint taskforce, which includes the CIA and the FBI," has been investigating whether Russians may have sent money to Trump's organisation or his election team.
In contrast to his actions over the Clinton letter, Comey stuck to convention in not talking publicly about the Russia probe. Yet at a Senate briefing on Saturday on Russian election meddling, Comey refused to even confirm whether he is conducting an inquiry into Trump ties to Russia.
The Independent reported that former MI6 agent Christopher Steele - who had contact with the FBI - became frustrated at lack of action from the bureau over his disputed file of memos on unconfirmed links between Trump and the Kremlin. He was so concerned about the material that at the end he was working without pay. The Independent said "he came to believe there was a cover up, that a cabal within the bureau blocked a thorough inquiry into Trump". The Senate intelligence committee is to investigate possible contacts and hacking.
The Democratic National Committee was hacked - allegedly by Russians seeking to influence the election in Trump's favour - and hacked private emails from the account of Clinton campaign chief John Podesta were doled out daily by WikiLeaks.
The slow release of bad news bolstered negative perceptions of Clinton. Fake news spilled into the campaign on social media, helping to boost toxic levels of negativity and distrust.
The US media saw the Clinton private server story as a weight to balance Trump's mountain of disqualifying dodginess - from lies, bigotry, assault claims, incitements to violence, a call for Russian hacking, conflicts of interest, failure to release his tax returns, Trump University and Trump Foundation.
The aim was to demonstrate traditional fairness to both sides, even though the issues simply weren't equivalent. It has become a left-wing meme to list Trump's various unprecedented scandals and then cry "but emails!"
The candidate's past
As a candidate, Clinton carried both lengthy, positive work experience and negative baggage. Her name recognition and national standing instantly recalled long service, achievements, missteps, rumours, myths, largely manufactured scandals and real ones.
Republicans turned the Benghazi incident - a 2012 attack in which four people died, including an ambassador - into a major Clinton failure. (For comparison, during the George W. Bush Administration Politifact says there were 13 attacks on US embassies and consulates at which 66 people, mostly non-Americans, died).
Republicans accused Clinton of having put important information at risk with her past use of the private server. Clinton's previous money-raising speeches and ties to rich donors got stirred into the pot. The campaign chimed with the take of 'shifty Clinton' that her opponents pushed.
As someone who spent many years thinking about running for president and was a key Republican target, Clinton should have been sharper at avoiding traps.
Not enough fervour
Election data suggests that Clinton lost because too many Democrat-leaning registered voters stayed home.
FiveThirtyEight reported that registered voters who didn't vote on election day were more Democratic-leaning than the registered voters who turned out.
"Given how closely party identification tracks with vote choice, the disparity in turnout probably cost Clinton the election," it said. "Had the non-voters cast a ballot in accordance with their party identification, Clinton's advantage over Trump nationally would have expanded by about two to three percentage points. That almost certainly would have been enough to flip enough states for her to win the Electoral College."
The biggest reason given by non-voters for staying home was that they didn't like the candidates. Younger voters were more likely to stay home than older voters. Non-white and Hispanics were more likely to stay home than white voters. These trends favoured Trump.
Vox writer Matt Yglesias tweeted: "Trump got 46 per cent of the vote while dominating among voters who disliked both candidates. Converting his core fans isn't necessary to beat him."
Inertia and timing
Parties have their own status levels and seniority - and it doesn't always work in their own favour with the wider public. The world can change at a quicker pace than leadership elites are ready for.
In 2007, Clinton was the favourite to win her party's nomination. It took a charismatic upstart to jump in where more senior politicians feared to tread and take her on. Barack Obama turned out to be the right candidate for 2008, winning in a general election 7 per cent landslide. Still, the fact that it was a 'change' year and a riskier pick was required was easier for Democrats to see after two terms of George W. Bush.
In 2015, Clinton was again the favourite. Big names like Vice-President Joe Biden and Senator Elizabeth Warren and younger stars such as Senator Cory Booker stayed out. Clinton was 'owed' after 2008 and the party elite was behind her. She was Obama's chosen heir.
Yet after nearly two terms of a Democrat government and with the economy still gradually recovering from recession, objectively this was another year that favoured a 'change' candidate over an 'experience' one. It was time for an Obama '16 to jump in if there was one.
Third term or new start
The Democrats - and many others - were blindsided by other factors. Obama had good favourability ratings for most of last year, unemployment was down, the economy was growing, the recession was in the rear view. Would that over-ride anger at past economic pain? How much could the Democrats argue against their own legacy and president? Could the party get away with a baton-change and continuity rather than a full-throated renewal?
And perhaps a baton-change could have worked with a Biden/Warren ticket - featuring clearer messages, more rhetorical passion, appeal and promise than Clinton/Tim Kaine.
Generally, after losing control of the House in 2010 and the Senate in 2014 the cupboard for strong alternative candidates was thin. Clinton's only competition was an ill-fitting option - an elderly, left-wing career senator who was essentially an independent.
Bernie Sanders did have a sharp message on banks and reforming Wall Street and delivered what his supporters wanted to hear with a passion and authenticity that appealed to disgruntled younger voters. The winds of change settled behind Sanders, who - unlike Obama - lacked the wider credibility within the party beyond his core believers to beat Clinton. His movement felt like a takeover to many in the party.
The Bernie revolution
The Obama coalition - liberals, minorities and young voters - was divided between the two, with progressives and younger voters preferring Bernie and African Americans, Hispanics, moderates and older voters going for Hillary.
Despite Sanders dominating discussion and capturing imaginations during the primary, by any measure Clinton won easily with the quiet majority: by 2842 delegates to 1865; by 34 contests to 23; by 16.9 million votes to 13.2 million and by 55.2 per cent to 43 per cent. But the clash between the progressive and moderate wings became bitter and carried on to the convention in August, long after Sanders lost.
Did the sniping contribute to a gradual erosion of Clinton's reputation, a rise in her unfavourable rating? Was he doing the Republicans' work for them? RealClearPolitics.com figures show Clinton started 2016 with an unfavourable rating of 50.8 per cent and a favourable rating of 42.3 per cent - an 8.5 per cent difference. By July 30, that had blown out to 56 per cent unfavourable and 38 per cent favourable - an 18 per cent difference.
The server row contributed - when Comey called off the investigation on July 5 Clinton's poll numbers suffered a hit of about 2 per cent.
But Sanders took a very long time to concede and try to talk his supporters around. He did support Clinton in the general campaign. Bitterness remains on both sides, with 'but Bernie would have won!' being a mocking meme for Hillary supporters. Some Sanders supporters clearly chose to support third party candidates or could simply not be persuaded to vote for Clinton. In Michigan, Pennsylvania and Wisconsin, the Green Party's Jill Stein received more votes than Trump's margins of victory.
The impact of gender
One of the hard-to-estimate factors is how much did gender and sexism play in the defeat of the first female presidential nominee. Clinton was up against an opponent dogged by accusations of assaults on women and sexist comments and yet he still won. Trump is historically unpopular, with worse favourability ratings during the campaign than Clinton, yet he was still preferred. In both the primary and general elections, Clinton struggled for media attention against Sanders and Trump. Clinton decisively carried the liberal bastions of major cities - a key reason why she ended up winning the popular vote by about 2.8 million. The 'hidden Trumpers' that state polls under-estimated and third party votes meant Clinton lost key Electoral College swing states by small margins. For women who wanted to see the first female president, her loss was a sickening blow. Perhaps the first step going forward should be the election of a female vice-president to get voters used to the idea of a woman commander-in-chief.
Problems with strategy
Much of the general election discussion and Democratic strategy focused on Trump's character.
It was eerily like 2004 when Democrat nominee John Kerry prosecuted George W. Bush for America's overseas wars. Clinton, like Kerry, appeared to have the winning arguments and was thought to have 'won' the debates. And as in Clinton's case, the attacks that brought down Kerry - Swiftboat, French-speaking and windsurfing - seemed petty.
But Trump was far more successful at transmitting basic ideas, especially that help was at hand for those who blamed trade deals and globalisation for their problems. In actual fact manufacturing jobs have declined for years and automation will accelerate. Clinton's campaign lacked the simplicity necessary in a world where many people feel drowned in complexity.
Clinton has admitted she's not a natural, inspiring orator. Her strength is intelligence, analysis and organisation. It is easy to imagine Biden getting across to rust-belt voters that he felt their hurt. As DNC chair contender Pete Buttigieg put it yesterday: "We were so busy talking about Donald Trump that [voters] were saying, who's talking about me?" There was also a woolliness to Clinton's basic pitch of 'stronger together' and basic purpose - simply enacting Obama's third term?
She tried to shore up her defences by arguing she was a change agent, including some of Sanders' policies and surrounding herself with more dynamic surrogates such as Obama, Michelle Obama, Bill Clinton, Biden, Warren and Sanders.
Her convention was well-organised to show her at her best and she performed well in the debates. Both gave her lengthy poll boosts. The Clinton team's adverts and online game seemed sharp.
A possible mistake was chasing votes in red states like Texas and Arizona at the expense of keeping blue swing states in line. Yesterday DNC interim chair Donna Brazile said: "I'm not going to sugarcoat it: We failed ... We got cocky about our invincible blue wall, and then we saw it crumble because of just a few thousand votes in Pennsylvania, Michigan and Wisconsin."
Great speakers needed
The Democrats' most successful politicians in the last two and a half decades were - when they first won - charismatic, intelligent, uplifting communicators and lightly-experienced.
Bill Clinton was the governor of a small state. Obama was a junior senator. Mostly they were fresh faces to the public. If Bill Clinton and Obama were A-level candidates, the party has too often chosen B-level: Michael Dukakis, Al Gore, Kerry and Clinton. Kaine is another in this vein - a successful regional politician but casting too small a rhetorical shadow for the biggest stage. Perhaps a more dynamic running-mate could have helped Clinton.
Hillary Clinton was vastly qualified and had the potential to be a thoughtful, careful, pragmatic leader in dangerous times. But her loss confirms that to win convincingly and safely, the party needs a charismatic great communicator with little baggage.
Anything less and it gets into a massive, tight dogfight because of the deeply polarised nature of the electorate.