WASHINGTON • United States President Barack Obama closes the book on his presidency with a farewell speech in Chicago (10am today Singapore time) that will try to lift supporters felled by Mr Donald Trump's shock victory.

Mr Obama's last trip on Air Force One will be a pilgrimage to his adoptive home town, where he will address a sell-out crowd not far from where he accepted the presidency eight years ago.

Fans have braved Chicago's frigid winter to collect free tickets, which sold for upwards of US$1,000 (S$1,430) a piece on Craigslist.

Mr Obama's cross-country trek would be a trip down memory lane, were it not right in the middle of a tumultuous presidential handover.

The 2016 election campaign has raised serious questions about the resilience of US democracy.

Democrats, cast into the political wilderness with the loss of the White House, the Senate and the House of Representatives, plus a majority of state Houses, are struggling to regroup.

With an approval rating hovering around 55 per cent, Mr Obama will hope to steel them for new battles ahead. Lead speech-writer Cody Keenan said the address will be about Mr Obama's vision for where the country should still go.

Having vowed to take a back seat in politics, Mr Obama, in his second act, could yet be as politically engaged as Mr Jimmy Carter - whose post-presidency has remade his image as an elder statesman.

Many Obama aides are reassessing their future and mulling over a return to the political trenches. Mr Obama's foundation is already gearing up for a quasi-political role - funnelling idealistic youngsters into public life.

"Chicago is not just his home town - it is where his career started," said Mr Keenan. And now, it is also where Mr Obama's presidential career will effectively end.

AGENCE FRANCE-PRESSE