The reasons are complex; the goadings of Ross Perot, the spreading influence of radio talkshow hosts, coupled with a genuine sense that special interests have taken over the government of the country. Not least of them, however, is the employment of financial scandal as a weapon of partisan political war.
The trend can be dated to the downfall of Speaker Jim Wright, a Democrat, in 1989. Wright was forced out for accepting gifts from a property developer and circumventing House rules on outside income; his disgrace, however, was largely engineered by a new generation of Republican congressmen, led by Newt Gingrich (who might just be Speaker himself in three months' time). The next victim was Tony Coelho, a star Democrat from California, who resigned after allegations linking him with junk-bond financier Michael Milken. Then came the saga of the 'Keating Five' group of Senators - Republicans as well as Democrats - who protected the savings and loan pirate Charles Keating and, most recently, the separate shenanigans at the House Bank and Post Office.
Each affair was different. Yet each contributed to the erosion of trust in Congress which is the hallmark of the 1994 mid-term elections, now just a fortnight away. Jim Wright and Tony Coelho had the wrong friends and belonged to the wrong party. The Keating scandal suggested that the feeble oversight of the savings and loans industry by Congress was not an accident.
The House Bank debacle turned the spotlight on the perks rife on Capitol Hill (in this case members' right to free overdrafts), reinforcing the perception that Congressmen were above the law.
Most serious, though, was the House Post Office scandal, which last summer led to the 17-count corruption indictment of Dan Rostenkowski, 36 years a congressman and chairman of the tax-writing Ways and Means Committee.
'Rosty', Chicago politics made flesh and a legendary figure on the Hill, faces trial on charges he used dollars 700,000 ( pounds 437,000) of public money for private purposes, some dollars 22,000 of it in the form of free stamps converted back into cash.
Mr Rostenkowski's alleged misdeeds fuel every public suspicion about Congress: a club of insiders in a city populated by lobbyists, lawyers, journalists and other politicians, oblivious to the needs of the country, and concerned mainly with feathering its own nest. Media coverage has revealed a world in which influential politicians are treated to lavish meals by interest groups, whisked by corporate jets to all-paid golfing weekends masquerading as business meetings, and funded by shadowy political-action committees. Such behaviour is quite legal. But it does not play well in Peoria.
In fact, the image is unfair. Despite uproar on the talkshows each time they award themselves a salary increase, most Congressmen work exhausting hours for far less (around dollars 130,000 a year) than they could earn outside.
Despite the headline cases, blatant corruption is comparatively rare in US politics. No longer do Congressmen's offices come equipped with a fitted safe in which to store fatbrown envelopes brought by supplicants.
Mighty lobbies such as the National Rifle Association no longer automatically have their way. US disclosure laws are stiff and the post-Watergate media are reared to be aggressive. The real problems are Congress's inability to make even cosmetic changes that would improve its image, and the vast and ever-increasing cost of getting sent to Washington in the first place.
In the wake of the Rostenkowski affair, both houses might have been expected to make at least a gesture of contrition. But partisan squabbling blocked a Bill that would have tightened registration and disclosure rules for lobbyists, and banned Congressmen and their staff from accepting even a tuna sandwich purchased by a third party. Not an earth-shattering step, but one that might have helped assuage the voters' wrath.
Far more revealing was the collapse of campaign finance reform. If money warps the system, it is at this stage. The cost of political campaigns is now stratospheric. In this year's California Senate election, the two candidates have been spending dollars 100,000 a day since January, a total of dollars 27.5m so far and rising. A few, like Michael Huffington - or Ross Perot in the 1992 presidential race - can pay out of their own pocket. For the more impecunious, even in contests less expensive than California, a campaign can boil down to endless fund-raising.
Hence the importance of six-figure contributions from, say, the health-insurance industry, which are unlikely to be without impact on the recipient's views on health-care reform. For years, there have been attempts to change the system; Bill Clinton, too, promised campaign-finance reform when he arrived in Washington in January 1993. His effort proved half-hearted. But against a cross-floor alliance, it never stood a chance.
The Bill that emerged late in the session would have curbed contributions and provided for Senate and House candidates who observed spending limits to receive public money to help them match up to their opponents who overstepped the mark. But under today's unregulated system, it is far easier for incumbents to raise money. Small wonder that when push came to shove, neither party on Capitol Hill wanted to make any changes. Thus, members of Congress will continue to amass vast sums of money, usually for the next campaign but sometimes, as intermittent embezzlement cases show, for private use as well.
And so the downward spiral continues. As the standing of Congress crumbles, even incumbents opt to run against their own institution - only increasing public cynicism and the ammunition available to the Perots, the Rush Limbaughs and the advocates of restricting the number of terms a member of Congress may serve. In 1994, Democratic feet are being held to the fire; but if they become the majority party on 8 November, the Republicans, led by Speaker Gingrich, can expect similar treatment next time around. Distrust of central government is as old as the United States. But even the United States has not yet learnt to function without government.
Tomorrow: Italy (Photographs omitted)