Shortly after Richard Nixon's triumphant re-election in 1972, the great American Jewish essayist Milton Himmelfarb sought to explain the voting behaviour of one of the few groups that had remained stubbornly resistant to the president's apparent charms. Jews, he wrote, "earn like Episcopalians and vote like Puerto Ricans".
While much else has changed about American politics in the intervening four decades, Mr Himmelfarb's aphorism looks set to remain as true when Americans go to the polls in November as it was when Mr Nixon occupied the White House.
As the general election campaign kicked off in earnest following the Labour Day weekend, Gallup released new polling showing that American Jews favour Hillary Clinton over Donald Trump by a margin of nearly 30 per cent. Only one religious group - US Muslims - gave Mrs Clinton a higher rating.
The results buoy Democrat hopes that Mrs Clinton may exceed the 70 per cent of the Jewish vote won by Barack Obama four years ago. In the last 40 years, only twice have Republican presidential candidates - Ronald Reagan in 1980 and George Bush in 1988 - managed to win the support of more than one in three Jewish voters. In 1992, when Bill Clinton ran for the White House for the first time, Jewish Democratic support hit 80 per cent.
The survey followed the release of a poll of Florida Jewish voters last month which showed the Democrat presidential standard-bearer beating Mr Trump by 66 to 23 per cent in the state. Orthodox Jews, however, constitute an exception: 66 per cent of them intend to back Mr Trump. They are, though, estimated to constitute less than 10 per cent of the state's Jewish population.
But, with the election less than eight weeks away, and the gap between the two candidates apparently narrowing nationwide, Jewish Democrats are predicting that the "kosher vote" could prove critical in a number of battleground states. In July, they launched "Jews For Progress", a well-funded campaign aiming to mobilise Jewish voters in "swing" states such as Florida, Ohio, Pennsylvania, Nevada, Colorado, Virginia, Iowa and New Hampshire which, many believe, will decide who occupies the Oval Office next January.
The two states with the highest percentage of Jewish residents - New York and New Jersey - are both heavily Democratic. By contrast, while Iowa and New Hampshire have relatively small Jewish populations - just over 6,000 in the case of the former and around 10,000 for the latter - each have seen extremely close races in recent elections. In 2000 and 2004, for instance, Iowa was decided by less than one per cent of the vote. In Florida, the state with the third highest proportion of Jews, recent polls have seesawed between narrow leads for Mrs Clinton and Mr Trump.
The poll of Florida Jews underlined the distinctly liberal bent of US Jewish voters. Three-quarters of those surveyed opposed the Republican presidential candidate's signature policy of banning Muslims from entering the US - a figure 16 points higher than among US voters in general.
Mr Trump's seeming lack of appeal to Jews does not surprise Alex Soros, son of the billionaire investor George Soros and chair of the Jewish liberal pressure group Bend the Arc Jewish Action. "History has taught us," he suggested recently, "where divisive and xenophobic rhetoric can lead."
