Trump proves himself unfit for presidency every day: Obama

"For all the progress we've made, if we don't work as hard as we can in these next 16 days, all that progress could be out of the window. Because competing for the job I currently hold, you've got a guy who proves himself unfit for this office every single day, every single way," Obama said at an election rally in Las Vegas, Nevada.

"On the other side, you've got somebody who is as qualified as has ever run for the presidency -- Hillary Rodham Clinton," he said amidst applause from the audience.

Obama said for years, Republican politicians and the far-right media outlets have pumped up all kinds of crazy stuff about him and about Clinton.

"They said I wasn't born here. They said climate change is a hoax. They said that I was going to take everybody's guns away. They said that, when we were doing military exercises that we've been doing forever, suddenly this was a plot to impose martial law. This is what they've been saying for years now. So, people have been hearing it, and they start thinking, well, maybe this is true," he told the audience.

"So if the world that they've been seeing is that I'm powerful enough to cause hurricanes on my own, and to steal everybody's guns in the middle of the night, and impose martial law, even though I can't talk without a prompter then is it any wonder that they end up nominating somebody like Donald Trump?" Obama said.

The fact is that there are a lot of politicians who knew better, he noted. "But they went along with these stories because they figured, you know what, this will help rile up the base, it will give us an excuse to obstruct what we're trying to do, we won't be able to appoint judges, we'll gum up the works, we'll create gridlock, it will give us a political advantage," Obama said.

The US President said the politicians just stood by and said nothing. "And their base began to actually believe this crazy stuff. So Donald Trump did not start this. Donald Trump didn't start it. He just did what he always did, which is slap his name on it, take credit for it, and promote it. That's what he does," Obama said amidst applause.

"And so now when suddenly it's not working, and people are saying, wow, this guy is kind of out of line, all of a sudden, these Republican politicians who were okay with all this crazy stuff up to a point, suddenly they're all walking away -- 'Oh, this is too much'," he said.