Barack Obama is speaking a lot of Spanish nowadays. In addition last weekend to releasing the first advertisement in which a presidential candidate speaks directly in the language, Mr Obama is already in a head-to-head fight with John McCain for what many election analysts believe will be the key ethnic swing vote in November.

On Wednesday Mr McCain and Mr Obama completed their third consecutive day campaigning in the south-west, which includes New Mexico, Nevada, Colorado, Utah and Arizona, targeted by both men as important swing states.