In a country where class politics and class organizations are weak, it's too easy to dump on the white working class as a bunch of know-nothings when the problem is a political class that is a bunch of do-nothings. That doesn't mean there isn't a problem here. When asked which candidate is most likely to advance the economic interests of you or your family, white people backed Romney 50 to 37 while non-whites backed Obama 71 to 22. That kind of discrepancy cannot just be put down to white people being better off.

Since the mid-60s Republicans have seen an electoral opportunity in appealing to the basest, racist sentiments of a section of the white electorate. What became known as the "Nixon strategy" aimed to use the dog whistle of racial symbolism - like "Welfare Queens" and "Willie Horton" - to draw white southerners into the Republican fold and peel off disaffected whites in the north too. It worked. Since the second world war, Democrats have won the presidency with the white vote alone only once - in 1964. One of the appeals for some whites of voting Republican is a desire to maintain whatever limited racial privileges they have acquired over the years combined with a fear that what little they have will be taken away by feckless non-whites and undocumented migrants. While in Nevada in 2010 I asked a white Republican without health insurance why she wouldn't support a candidate who might give it to her. "I never really got into that Obamacare insurance stuff," she said. "My mind is focusing 250% on this illegal immigration."

None of this means all Republican supporters are racist. But it does suggest they make their appeal on racial grounds and, as the poll shows, it is effective. But it won't be for ever. Whites will be a minority in the US in about 30 years. Republicans' appeal to Latinos is already pitifully low and has made several western states, including Nevada, New Mexico, Arizona and Colorado, extremely competitive.

Nonetheless, time and again during the Republican primaries Republicans evoked racial themes in the whitest places. "I don't want to make black people's lives better by giving them somebody else's money," said Rick Santorum in Sioux City. "I want to give them the opportunity to go out and earn the money."

"Right," said one audience member, as another woman nodded.

"And provide for themselves and their families," Santorum added.

The black population of Sioux City is 2.9%. In Woodbury County, in which Sioux City sits, 13% of the people are on food stamps, an increase of 26% since 2007, with nine times as many whites as blacks using them.

Just a few days later, in Plymouth, New Hampshire, Newt Gingrich said: "I will go to the NAACP convention and explain to the African-American community why they should demand paychecks [instead of] food stamps." African-Americans make up 0.8% of Plymouth's population. Food stamp use in Grafton County is 6% - a 48% increase since 2007.

Those who are struggling and believe Romney will improve their economic lot are wrong, regardless of their race. Eight years of George W Bush proved that. But it does not follow automatically from that that their home should be supporting Democrats under whom things have gotten less bad less quickly. True, those are the only two choices on offer. But if you're poor they are not great choices. What they need is a party that represents their interests. In a country where corporate money chooses the candidates and therefore shapes the debate that will demand a change in politics, not just politicians.