The US presidential election campaign has focused a lot on strengthening the country's middle class, but little has been said about low-income families, particularly those in poverty. There were more than 46 million Americans living in poverty last year (15 per cent of the population) a figure that has been steadily rising from about 33 million people in poverty a decade ago. When the economic crisis hit in 2008, about 40 million were affected and the poverty threshold for a family of four in the US is just over $23.000. But some people have criticised that definition as too low, particularly for families living in cities. Al Jazeera's Andy Gallacher reports.