The anger and fear that fueled people in the UK to depart the EU, as well as the extraordinary and unexpected success of Donald Trump and Bernie Sanders in the United States, is in many ways understandable. Sadly, the global economy has left millions behind and the mainstream political parties have not adequately addressed their plight.

A significant percentage of those living in western societies see a bleak future ahead of them, their children and their grandchildren. They are desperate and are more open than ever before to radically different messages and promises from political figures.

Whether they fully grasp it or not, though, and as borne out by the topsy-turvy political year 2016 has been, they are powerful. They are numerous and the significant defeats they have inflicted upon the establishment speak for themselves.

The question, then, in an American context becomes: Could a third party emerge from this upheaval? The first point, of course, which needs to be made is that graveyards are full of political scientists and commentators who either predicted that a third party in the US would come into being or actively tried to start one.

The Republicans and Democrats have a mutually beneficial stranglehold on the system. The financial costs of starting a new party are incalculable. The “first past the post,” “winner take all” electoral system in the US militates against a third party. And strong, appealing leaders with the requisite political skill are hard to come by.

That said, the alienation from traditional, conventional politics and politicians in the US cannot be overerstated.

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In particular, there is a sizable gulf in thinking between the leadership of both parties and the American people on the role of the US in the world. Virtually every opinion poll taken in recent years indicates that Americans generally are opposed to military interventionism except when vital national interests are at stake – and they define these interests far more narrowly than men and women in Washington, DC do. Americans are very dubious about the merit of trade deals which have manifestly accelerated the decline in the once mighty manufacturing sector and exacerbated the problem of income inequality. And they don’t want to accept as many immigrants.

Similar to those British voters who endorsed leaving the EU, these tens of millions of Americans are nationalists, not internationalists. There are some worthy aspects to this nationalism and there are some undeniably ugly facets of it, too.

The challenge for the Republican and Democratic parties is how to reach out to these disenchanted people. Donald Trump and Bernie Sanders have clearly struck a chord this year, but their messages and massaging have been some distance from their respective party platforms, which are informed to no small extent by moneyed interests.

The resistance of some of Hillary Clinton’s backers to any skeptical language about trade at the upcoming Democratic National Convention is telling. It is unlikely that either party will be a hospitable place for those who have found so much to like in Trump and Sanders.

The potential for a third party – or third way – in American politics was recognized in the 1990s by the billionaire, H. Ross Perot, and the columnist, Pat Buchanan. The anger and fear weren’t as pronounced then as now, however. Moreover, Perot was too eccentric and egotistical and Buchanan too doctrinaire and far to the right to build a broad enough movement. Yet it is likely that both would have fared better if the context in which they made their attempts was more akin to now.

In short, there is definitely something there, but the obstacles, institutional and otherwise, are probably too large to overcome. It would take an extraordinary leader, many capable people under him or her and an awful lot of money to start a third party. It doesn’t appear to be in the offing in the near future. Meanwhile – even though Sanders has lost his fight for the Democratic presidential nomination and Trump is unlikely to prevail in November – their voters will cause the commentariat to rethink some of our most fundamental assumptions about American politics for years to come.

* Larry Donnelly is a Boston attorney, a Law Lecturer at NUI Galway and a political columnist with and Follow him on Twitter at @LarryPDonnelly.