Hillary Clinton's election loss was simply the a recent example of a global rout of center-left political parties. Today in France we could see the most spectacular example yet. If Benoît Hamon fails to get at least 5% of the votes, then the Socialist party's campaign expenses will not be reimbursed, bankrupting the PS.
That means a center-left political party could go from being the ruling party to complete collapse in just one election cycle.

It's no small coincidence that faith in neoliberalism is collapsing at the very same time.

Joseph Stiglitz, the Nobel Prize-winning economist and former adviser to US President Bill Clinton, says the consensus surrounding neoliberal economic thought has come to an end...
"We've gone from a neoliberal euphoria that 'markets work well almost all the time' and all we need to do is keep governments on course, to 'markets don't work' and the debate is now about how we get governments to function in ways that can alleviate this," he said.
In other words, Stiglitz says: "Neoliberalism is dead in both developing and developed countries."

Stiglitz is not exaggerating. Even the IMF says that “Neoliberalism: Oversold?” That's like the Pope asking if the Virgin Mary was fooling around.
The reasons for the collapse of neoliberalism are myriad and systemic.

Earned income has been supplanted by unearned income.
Neoliberal policies are everywhere beset by market failures. Not only are the banks too big to fail, but so are the corporations now charged with delivering public services. As Tony Judt pointed out in Ill Fares the Land, Hayek forgot that vital national services cannot be allowed to collapse, which means that competition cannot run its course. Business takes the profits, the state keeps the risk.
The greater the failure, the more extreme the ideology becomes. Governments use neoliberal crises as both excuse and opportunity to cut taxes, privatise remaining public services, rip holes in the social safety net, deregulate corporations and re-regulate citizens. The self-hating state now sinks its teeth into every organ of the public sector.

So with free-market fundamentalism in retreat, why is the center-left being destroyed along with it?
Stepping back and seeing the entire landscape would allow Democrats to see the political landscape has changed, and the need for fundamental reforms.

So why is the centre-left by and large not benefiting from the failures of their political opponents? The deep reason lies in its absorption of the policies of the centre-right, going back almost three decades: the acceptance of free trade agreements, the deregulation of everything, and (in the eurozone) of binding fiscal rules and the most extreme version of central bank independence on earth. They are all but indistinguishable from their opponents.

The story is much the same in the United States, where the lion's share of deregulation has been done under Democrats.

The size of the problem is staggering.

Overall, the total vote share for the continent's traditional center-left parties is now at its lowest level since at least World War II. Like the Democrats, these parties have been marginalized, with little influence over policy as the right prepares to place its stamp on the Western world in a way that could endure for decades.
"If the left and the center-left don't get their act together, then we're looking at a period of very unstable right-wing hegemony," said Alex Callinicos, a European studies professor at King's College London.

The fact is that the center-left is unable to "get their act together" because their entire philosophy means a continuation of the current system, a system that has unquestionably failed on every level.
For instance, the membership of the UK Labour Party attempted to move the party to the left. The party leaders, led by Blairites, have undermined their membership at every turn.

Corbyn, meanwhile, has struggled to hold his party together as Labour members of Parliament have overwhelmingly said they have no confidence in his leadership. Blair and his allies have argued that Corbyn will simply guide the party to continued irrelevance.
“You win from the center; you win when you appeal to a broad cross section of the public; you win when you support business as well as unions,” Blair, who guided the party to three straight national election victories, said in a speech last year. “You don’t win from a traditional leftist position.”
...Across Europe, the center-left has had little to offer those voters, who have looked elsewhere — including the far right.

To put it simply, the establishment left has no clear alternative. Everyone with a non-neoliberal vision of the world has been either marginalized or silenced.

For those who bemoan the rise of the populist right, the challenge is clear: you can’t beat something with nothing and if the left can’t come up with more viable and attractive solutions to contemporary problems than those offered by its competitors it can expect to continue its slide into the dustheap of history.

The neoliberal centrists, such as the Clintons and Blairites (and countless wealthy backers) have spent decades gutting and destroying left-wing voices and ideas, while the right-wing rampaged.
Now that they are gone and all they have built lies in ruins, there is no leftist infrastructure to create an alternative reality. It has to all be created from scratch. All the left has to work with are shattered pieces of dated history, and pointless, feel-good, identity politics.
This leaves neoliberalism in place, staggering along in zombie form. Not alive, but still consuming the living.