The negative approach taken by the McCain-Palin campaign has coincided with a series of aggressive expressions towards the Democratic nominee over his Left-wing associations and background. Apart from highlighting John McCain's connections to the Keating Five scandal, the Obama campaign has perceived benefits in staying above the fray but is always prepared with a defence when attacked. With Mr Obama leading in the polls and only 24 days to go before the US presidential election, the series of outbursts have sparked the interest of the Secret Service, which guards the candidates and other dignitaries. They launched a brief investigation after...