The Census Department figures mean that exactly one in seven of the population live below the poverty line, defined as an annual income of dollars 13,924 (about pounds 7,000) for a family of four, or dollars 6,932 for an individual living alone. Ethnic minorities are particularly hard hit: one in three of all blacks is poor, and among Hispanics the proportion is 29 per cent.
Although argument rages over the validity of the figures - conservative critics say that the exclusion of non-cash benefits like food-stamps, Medicare and public housing means the poverty rate is grossly exaggerated - they support one of Democratic candidate Bill Clinton's constant themes, that 12 years of Republican rule have just seen the rich get richer and the poor poorer.
The reaction from the White House was muted and defensive: the recession, said Marlin Fitzwater, the presidential spokesman, was 'bound to have a serious effect on income and poverty levels'.
A separate government report this week, which also underlines just how much the recession is hurting Mr Bush's re-election bid, showed Americans' real income dropped an average 2 per cent in 1991. In key battleground states like California, Illinois and Ohio, the drop was even steeper, in the case of California - the biggest prize of all - 3.1 per cent.
The economic data has been a further boost for Mr Clinton, who picked up the formal endorsement yesterday of the country's union movement. In a speech to the AFL-CIO organisation here, he proclaimed the Democrats to be the champion of 'working men and women and the forgotten middle-class'.
Big Labour has long been wary of Mr Clinton, thanks to his pro-business policies as Governor of Arkansas and his earlier support of the planned North American Free Trade Agreement (Nafta) with Mexico. Yesterday, though, was a time to bury the hatchet in the common cause of ejecting the Republicans from power.
Mr Clinton, moreover, is refusing to endorse Nafta, at least until he sees details of the agreement, which have still not been released by the administration. To the AFL-CIO he was notably muted on the issue. Instead, he derided Mr Bush for his promise of unspecified 'across-the- board' tax cuts, and the pre-election carrots the President was doling out across the country this week.
The Democratic candidate described as a 'death-bed conversion' the President's sudden approval of a dollars 6bn sale of F-16 fighters to Taiwan, which reverses years of pro-Peking policies by the White House, but protects thousands of defence industry jobs in electorally vital Texas.
Mr Clinton appears to have weathered, for the time being at least, a new flurry of allegations over his Vietnam draft record. The Los Angeles Times reported this week that an uncle, now dead, had lobbied hard to delay the draft induction of the future presidential candidate in 1968, just after he had won his Rhodes scholarship to Oxford. Mr Clinton, however, denies he knew of such efforts, if indeed they took place.