Rancho Mirage, United States: The United States President Barack Obama on Tuesday hammered home his belief that Republican White House hopeful Donald Trump would not be elected, knocking his reality show past and penchant for drawing media attention.

Obama did not limit his criticism to the billionaire real estate tycoon, hitting out at ‘troubling’ statements from the entire GOP field of candidates seeking to replace him.

But he reserved his toughest remarks for Trump, offering a scathing assessment of why he thinks the American people will not elect him.

‘I continue to believe that Mr Trump will not be president. And the reason is because I have a lot of faith in the American people. And I think they recognize that being president is a serious job,’ he told reporters in California.

‘It’s not hosting a talk show or a reality show. It’s not promotion. It’s not marketing. It’s hard,’ he said on the sidelines of a summit with leaders and representatives of 10 Southeast Asian nations.

‘It’s not a matter of pandering and doing whatever will get you in the news on a given day. And sometimes it requires you making hard decisions, even when people don’t like it,’ Obama continued.

He also noted the need to be ‘able to work with leaders around the world in a way that reflects the importance of the office.’

‘During primaries, people vent and they express themselves,’ Obama said, alluding to Trump’s brash, take-no-prisoners style. ‘Oftentimes it’s reported just like entertainment, but as you get closer, the reality has a way of intruding.’

‘The American people are pretty sensible. And I think they’ll make a sensible choice in the end,’ he concluded.

The 69-year-old Trump, who for months has led opinion polls in the Republican race for the White House nomination, was scornful of Obama’s remarks.

‘This man has done such a bad job, he has set us back so far,’ the real estate magnate said in a television interview, adding however that in a way, being singled out — even for reproach — by the sitting US president was ‘a great compliment.’

Trump said Obama was ‘lucky’ that he did not run for the US presidency in 2012 as he had contemplated doing, otherwise the Democrat ‘would have been a one-term president.’

Trump lost the Iowa caucuses to Senator Ted Cruz early this month, but roared to victory in the New Hampshire primary last week. He holds a commanding 16-point lead over Cruz in South Carolina, according to a CNN poll.

Obama, whose successor will be chosen on 8 November, insisted that Trump was not alone in expressing unsettling proposals on the Republican campaign trail.

‘He may up the ante in anti-Muslim sentiment, but if you look at what the other Republican candidates have said, that’s pretty troubling, too,’ he said.

‘They’re all denying climate change. I think that’s troubling to the international community.’

No backing down on Supreme Court

In another challenge to his political rivals, Obama again insisted he would nominate a successor to late Supreme Court justice Antonin Scalia, and said Republicans were duty-bound not to hold up the process.

‘The Constitution is pretty clear about what is supposed to happen now. When there is a vacancy on the Supreme Court, the president of the United States is to nominate someone,’ Obama said.

He lamented the ‘venom and rancor in Washington,’ which he said had ‘prevented us from getting basic work done,’ adding: ‘This would be a good moment for us to rise above that.’

Almost as soon as Scalia’s death was announced Saturday, Republican Senate majority leader Mitch McConnell warned that the next president, not Obama, should name the ultra-conservative justice’s replacement.

The choice of a successor to Scalia could tip the balance on the high court — which effectively is left with four liberal-leaning justices and four conservative justices — and affect several major cases on its docket.