Obama Warns Biden Supporters Not To Be 'Complacent' Despite Polls

Barack Obama on Wednesday called on Joe Biden supporters not to be "complacent" despite favorable opinion polls ahead of the November election and attacked President Donald Trump in a rally speech.

The former president made the comments in his first public rally in support of Biden, warning of the errors in opinion surveys before Trump's shock 2016 victory.

"We can't be complacent. I don't care about the polls," Obama said at the drive-in rally in Philadelphia, in the battleground state of Pennsylvania.

"There were a whole bunch of polls last time. Didn't work out. Because a whole bunch of folks stayed at home. And got lazy and complacent. Not this time. Not this election."

Obama lashed out at Trump's record and provocative behavior as he sought to contrast him with Biden, his former vice president.

He said Trump had proved himself "incapable of taking the job seriously".

"This is not a reality show. This is reality," Obama said.

"And the rest of us have had to live with the consequences of him proving himself incapable of taking the job seriously."

Obama went on to say that "our democracy's not going to work if the people who are supposed to be our leaders lie every day and just make things up. And we just become numb to it."