This will be oldest presidential race in US history

In a country obsessed with the cult of youth, the battle for the White House is ironically coming down to a contest between a grandmother and a grandfather as Democrat Hillary Clinton and Republican Donald Trump fight it out for the top job, having edged out much younger rivals.

Grey power looks set to triumph — even if both candidates have chosen to sport copious blonde locks.

But the course ahead will be mined with challenges for 68-year-old Clinton and 69- year-old Trump as they head into the gruelling final lap that will demand huge reserves of physical and political stamina.