Donald Trump is a symptom representing an especially virulent strain of political opportunism that has erupted on the body politic and seems resistant to the usual antidotes of civility, custom and regard for the good of the country that have so often saved us from the most deleterious effects of political ambition and arrogance.

However, for all the angst he is causing among his own party and for all the attention he draws with his insult-riddled and racist bombast, Trump is not the disease. The real problem is deeply embedded in our political processes and in fundamental and deep rifts in the national consensus about government and its purpose. Those differences once were held in check by an impulse as basic as self-interest -- the willingness to concede something in order to gain or retain something else.

Our politics has been abducted, however, by unyielding ideologues who exhibit a kind of political fundamentalism that is oblivious to the wreckage left in the wake of its pursuit of some ill-conceived dogmatic purity.

In a masterful and exhaustive work published in January, Why the Right Went Wrong: Conservatism -- from Goldwater to the Tea Party and Beyond, political analyst E.J. Dionne Jr. traces the dysfunction of the current moment to the era of Sen. Barry Goldwater and his high-profile attempt to "ride roughshod rhetorically over government programs that were firmly rooted in American life."

Ronald Reagan, introduced during the Goldwater era and delivered by conservatives to the Oval Office, was accomplished at conveying a kind of social severity in disarmingly seductive tones. A latent strain of extreme individualism that had conceded certain issues as they applied to the common good -- earlier, Republican President Dwight Eisenhower had described himself as conservative on economics but liberal on human issues -- resurfaced. It became fashionable in the Reagan universe to see the government as the problem and free, unrestrained markets as the answer to all ills.

Freedom -- individual and otherwise -- could be disconnected, at least in certain imaginations, from the functions of government.

How we got to where we find ourselves today is overwhelmingly complex and, indeed, requires the length of a book to fold in the effects of economic crisis, the influence of religious interests, single-issue politics, globalization, and the browning of U.S. culture.

Arrogance of power and opportunism are hardly the province of a single party. In the immediate circumstance, however, Trump is the unintended consequence of allowing the worst of our collective instincts to flourish, like weeds gone wild in the garden of public virtue. And Republicans of longer term and longer vision than Trump are understandably in a panic.

Perhaps the unrelentingly crude visage that Trump has applied to our political discourse has finally shocked us into seeing the significance of the disconnect from traditional conservative concerns for the working class and for policies and programs essential to a just society.

It is dangerous to assign superlatives to any era of U.S. politics, which have always displayed a certain nasty, down-and-dirty quality. But this cycle warrants a superlative or two. In all the vicissitudes of politics we've witnessed in the past half century or so -- from assassinations to Watergate to Oval Office sex that led to impeachment, to the stunning elections of our first black president, to the rise of the tea party -- something most unusual is occurring in this election cycle.

Most of the major conservative commentariat, those who in any other cycle would swallow hard at disagreements and rally around the Republican front-runner, are beyond abandoning Trump. Many are openly arguing against his nomination. The party itself is wondering what it will do should he win the nomination, which increasingly appears inevitable. The party would do well to listen to its own best critics on the inside.

Taking political advantage of the Republicans' momentary dilemma will not solve the problem. Nor will electing another Democrat to the White House do much in the way of ending the standoff that seems to have become a permanent element of the U.S. government.

It will take leaders, particularly among conservatives, to speak courageously of returning the country to its moorings, tied securely to the understanding that a functioning democracy is an endless exercise in balancing interests, not a debate among unyielding ideologies or political fundamentalisms in which compromise is tantamount to sin.

Politics, government, compromise and common good are not dirty words. They represent the real strength of a pluralistic democracy. They are the fortifications that protect us from the kind of nativism and racially tinged invective as well as the juvenile sniping that has dominated so much of this election season.