The unlikely presidential campaigns of Donald Trump and Bernie Sanders have been the most entertaining in many years. Large crowds more reminiscent of sporting than political events routinely attend their campaign appearances. Television audiences eagerly tune in to televised debates, attracted less by the prospect of learning something new about Obamacare or Syria than by the spectacle of Trump dissing the hapless Jeb Bush or "feeling the burn" of Sanders' righteous indignation.

There is something different, even unprecedented, about the candidacies of Trump and Sanders. Their historic campaigns for the US presidency are nothing less than a reflection and a symptom of the central fact of US life today - the calamitous deficiencies of US ruling economic, political, and national institutions and the loss of legitimacy they are suffering from a US public fed up with the shortcomings of the status quo.

The new millennium has witnessed three seminal events in its young life - the attack on the World Trade Center in September 2001, the US invasion of Iraq in 2003, and the Great Recession.

Receding middle-class life

The US economy has not delivered for most Americans in decades. Incomes are stagnating and the dream of a comfortable middle-class life is receding.

These are not the consequences of a failure of the famed American work ethic, but of the distorted power and interests of US financial powers and the corruption of the titans of the US economy.

READ MORE: Why I'd vote for Trump, but you shouldn't

The successful attack on the US by al-Qaeda and the subsequent bloody and destructive war in Iraq revealed the rot at the core of US intelligence and political decision-making systems.

Trump's promise to make the US great again and Sanders' calls for a new American revolution are two sides of the same coin.

The entire process at the heart of the decision to wage war was manufactured on a lie. Who can forget the cascade of spurious claims at the heart of the debate?

The US political class - Democrat and Republican alike - led the chorus of US support for this misadventure, whose destructive legacy still dominates the news. Intelligence and military systems abetted the charade, applauded by a cheerleading press.

The digital age, which is supposed to open unimagined horizons of truth and knowledge to an engaged and educated public and to inform public debate on critical issues of national importance, instead metastasised into a vital tool in the creation and dissemination of official falsehoods, popular ignorance, and grievous misapprehension that paved the road to the invasion and occupation of Iraq.

US system gone haywire

These events are most often seen and understood as discreet and separate, interesting and important only in themselves.

The truth is that these seminal events in US life, and others associated with them, are not occurring in isolation, nor did they happen overnight. They are all the products of a US system gone haywire. They are signs of a much deeper malaise, requiring far more attention than the flaccid remedies that the US financial and political leaders have implemented.

These half-measures are not surprising. What else can be expected when you ask the fox how to repair the henhouse?

The unlikely if compelling candidacies of Trump on the Republican side and Sanders on the Democrat are incomprehensible without reference to these crises, which are themselves related to each other. Trump and Sanders don’t agree on the solutions to America’s problems but they are united in their view that making America great again requires no less than a revolution.

Americans are angry and frightened, not only because the failures of the system across a wide spectrum threaten the secure futures of their families but also because no one in the financial or political community is seen to be paying for their misdeeds or misjudgments, or indeed even recognises their severity.

READ MORE: Why I will vote for Bernie Sanders

Al-Qaeda's attack is dismissed as a one-off oversight. The wars in Iraq are blamed on the Iraqis, and lessons are said to have been learned from the Great Recession.

Popular anger is transformed into voter antipathy when its causes are not addressed or recognised. The support declared during the last debate of major Republican candidates for George Bush's conduct of the war in Iraq and their rejection of his responsibility for 9/11, and Hillary Clinton's association with Wall Street are the expressions of clueless politicians ill-prepared to address a public mood they do not understand.

Virulent antipathy

The voting booth is the place where today's virulent antipathy with the way things are is being registered. Not surprisingly, the pundits and professionals - those who profess to know how Americans think or seek to instruct them - have been flummoxed by the energised campaigns of renegades from the left (Sanders) and right (Trump).

Their energy stands in contrast to the somnambulance of the mis-anointed front-runners Bush and Clinton - heirs of storied families whose lustre has been perhaps fatally dimmed by the public's apparent belief that the traditional representatives of the US political system contesting the presidency are no longer deserving of their confidence.

Trump's promise to make the US great again and Sanders' calls for a new American revolution are two sides of the same coin. Each in its own way represents an authentic response of two political outsiders to the broad and all but unprecedented failures of a US system in recent times and the estrangement many Americans feel from their ruling economic and political institutions.

Each demands that leaders and institutions themselves be held accountable for the uncomfortable truths that each believes he is the only one bold enough to acknowledge - that Bush failed to protect the US, that the war in Iraq was based on a lie, and that traditional politicians - Republican and Democrat alike - are the source of the US' economic problems and the obstacle to their solution.

Geoffrey Aronson writes about Middle Eastern affairs. He consults with a variety of public and private institutions dealing with regional political, security, and development issues.

The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.