A protester burns an American flag during a rally against President Obama in Oakland July 23, 2012.
Grim findings have been coming thick and fast. Most Americans no longer see President Barack Obama as honest. Half think that he "knowingly lied" to pass his Obamacare health law.
Fewer than one in five trust the government in Washington to do what is right all or most of the time.
Confidence in Congress has fallen to record lows: in America, as in Italy and Greece, just one in ten voters expresses trust or confidence in the national parliament. Frankly straining credulity, a mammoth, 107-country poll by Transparency International, a corruption monitor, this summer found Americans more likely than Italians to say that they feel that the police, business and the media are all "corrupt or extremely corrupt".
Americans are also turning on one another. Since 1972 the Chicago-based General Social Survey (GSS) has been asking whether most people can be trusted, or whether "you can't be too careful" in daily life. Four decades ago Americans were evenly split. Now almost two-thirds say others cannot be trusted, a record high. Recently the Associated Press sought to add context to the GSS data, asking Americans if they placed much trust in folk they met away from home, or in the workers who swiped their payment cards when out shopping. Most said no.
The press is full of headlines about an American crisis of trust. That is too hasty. Lexington spent years in Asia and Europe reporting from countries cursed by official corruption and low trust among strangers. America is not that sort of society.
In genuinely low-trust societies, suspicion blights lives and hobbles economies. In China, even successful urbanites distrust business and government, worrying constantly about the food they buy and the air they breathe. Yet those same successful Chinese have little confidence in the poor. Chinese friends used to urge Lexington never to play Good Samaritan at an accident scene, insisting that anyone rich who stopped to help would be blamed for the victim's injuries and pursued for compensation.
It is true that America faces grave problems. Congress has had an unproductive year: shutting down the federal government was a notable low point. The Internal Revenue Service (IRS) confessed to subjecting Tea Party and other political groups to special scrutiny, enraging conservatives. But to put such antics in perspective, this year Italy's richest media tycoon and its ex-prime minister, Silvio Berlusconi, was convicted of tax fraud, of paying an underage prostitute and abuse of power.
In genuinely low-trust countries, tax evasion comes naturally: when those at the top cheat, only dupes follow the rules. But America shows few signs of surging tax evasion. The most recent IRS "tax gap" estimates found no significant decline in the proportion of taxes paid voluntarily and on time.
Nor are Americans at soaring risk of being ripped off in daily life. The latest survey of consumer fraud by the Federal Trade Commission found a fall in the prevalence of scams. Payment-card fraud is rising, but only in proportion with overall card use, says FICO, a fraud-management firm: crooked shop staff affect "percents of a percent" of transactions.
None of this justifies complacency. Americans are dangerously angry. But when they voice Italian levels of distrust for authorities, or sweepingly accuse fellow-citizens of being crooks, they are not describing reality. Here is a theory: Americans are instead revealing how deeply they are divided. Dig into headlines about "half of all Americans" thinking this or that, and large partisan or demographic divides lurk.
Take that poll finding that half of voters think Mr Obama lied to pass his health plan. Look more closely, and eight in ten Republicans think he fibbed, but fewer than one in four Democrats. As for headline GSS numbers about overall trust between Americans, they conceal a big race gap: for decades around 80% of black Americans have consistently said that most people cannot be trusted. The bulk of the recent decline involves whites becoming less trusting, says Tom Smith, the survey's director.
Explaining that decline is a complex business, but over the same period society has become more impersonal and more economically unequal. Robert Putnam of Harvard University, a pioneer in the study of "social capital", argues that Americans' trust in one another has been declining steadily since the "golden" aftermath of the second world war, when civic activity and a sense of community among neighbours were at a peak.
Trust in institutions has risen and fallen over that same post-war period in line with external events, plunging after the Watergate scandal, for instance, and during recessions. Yet something new seems to be happening. Anti-government cynicism is feeding on gulfs in society.
Conservatives think Democrats buy votes with welfare
Consider the crisis around Obamacare. Forget fussing about its useless website: websites can be fixed. The president's headache is that voters see his plan as welfare for the poor rather than a better way of delivering medical care.
That is exposing ugly divisions. Most starkly, a majority of whites think the law will make life worse for them, a National Journal poll found, while most non-whites believe it will help people like them. That in turn tallies with a big change over the previous 15 years: a collapse in support among conservatives for government safety nets.
This is America's real problem with trust. The country faces a crisis of mutual resentment, masquerading as a general collapse in national morale. Sharply-delineated voter blocs are alarmingly willing to believe that rival groups are up to no good or taking more than their fair share. Polls describing America as a hell-hole of corruption are not to be taken literally. They are a warning. America is not a low-trust society. But it risks becoming one.