Election fever rises as Obama backs Harris while Trump pushes America First

Former US president Barack Obama is planning to support to Kamala Harris' campaign in the must-win swing state of Pennsylvania, as Democrats fight to move the dial against Donald Trump just weeks before Election Day.

America's first Black president is set to lead a rally in the steel city of Pittsburgh on Thursday, his first stop on a tour of battleground states, to urge people to cast early votes for November's election.

Harris was in Nevada for a town hall on Thursday and heads to Arizona on Friday to reach out to Latino voters. But the White House said she had also taken part in a virtual briefing on deadly Hurricane Milton, which crashed into Florida overnight.

Former president and Republican candidate Trump stepped up his criticisms of Harris and President Joe Biden over their response to the hurricane.

"Hopefully on January 20 you're going to have somebody who's really going to help you," Trump said in a video message to the people of Florida, where he lives.

Obama says 'all hands on deck'

Democrats are hoping Obama, who was in the White House from 2009 to 2017 before Trump's term, could give Harris a boost in a race that remains neck-and-neck.

Despite an initial surge in the polls after she dramatically replaced Biden as Democratic nominee in July, and a reported $1 billion in fundraising, Harris and Trump are still effectively tied nationwide and in swing states.

"President Obama believes this is an all hands on deck moment which is why he'll be doing everything he can to help elect Vice President Harris," his office said.

Democrats have historically favored early voting over Republicans.

Trump has, meanwhile, repeatedly attributed his 2020 defeat by Biden to the use of mail-in ballots.

Obama remains hugely influential in the Democratic Party and quickly endorsed Harris, 59, after Biden ended his reelection bid.