 Media playback is unsupported on your device Media caption President Obama: "Sometimes it [being president] requires you...doing things that are unpopular" 
 
 Republican Donald Trump will not be president because it's a "serious job", President Barack Obama has said. More on the Trump campaign 
 
 Media playback is unsupported on your device Media caption Three things Trump says 
 
 Is Trump unstoppable? The electorate will not pick him, said Mr Obama, because "they recognise that being president is a serious job". From hotel mogul to candidate 
 
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 His chief rival is Texas Senator Ted Cruz, but one of his other rivals, the big-spending former Florida Governor Jeb Bush, will be hoping for a better performance after disappointment in Iowa and New Hampshire. He has won one state primary already, and leads the polls in South Carolina, where Republicans vote on Saturday. Mr Trump said he would deport 11 million undocumented immigrants, build a wall on the southern border paid for by Mexico and that Muslims should be stopped from entering the US. And the reason is because I have a lot of faith in the American people," said Mr Obama. Mr Trump responded by saying it was a compliment to be criticised by a president who had done so much damage to the country. Image copyright Twitter 
 
 Mr Bush tweeted the picture after taking questions at the premises of gun maker FN Manufacturing in Columbia, South Carolina. Mr Trump, a billionaire businessman, is the frontrunner in the race to be his party's choice for the White House. Image copyright Twitter 
 
 Within hours it had been retweeted 15,000 times and was met by outrage and parody. On Tuesday, a tweet by Mr Bush depicting a gun engraved with his name, alongside the word "America", provoked a strong reaction online. It's not a matter of pandering and doing whatever will get you in the news on a given day." And Piers Morgan, who used to host a primetime show on CNN and was well known for his stance against gun rights, said it was "appalling". "It's not hosting a talk show or a reality show, it's not promotion, it's not marketing, it's hard.
– He's said it before and he'll say it again: President Obama doesn't think voters are going to choose Donald Trump to succeed him. "I continue to believe that Mr. Trump will not be president," Obama told reporters on Tuesday at the ASEAN economic summit in California, per the BBC. "I have a lot of faith in the American people, and I think they recognize that being president is a serious job," he said. "It's not hosting a talk show or a reality show. It's not promotion. It's not marketing. It's hard. It's not a matter of pandering and doing whatever will get you in the news on a given day." Trump fired back after being asked about the remarks during a campaign event in South Carolina Tuesday night, reports the Washington Post. He said it was "actually a great compliment" to hear such comments from someone who has "set us back so far" and "done such a lousy job as president." Trump—who told Larry King in 2009 that Obama was doing a "really good job" after the "total disaster" of the Bush administration—said Obama is lucky that he didn't seek the nomination instead of Mitt Romney in 2012, "because you would have been a one-term president." (Obama also told reporters that he is going to nominate an "indisputably" qualified candidate to fill the vacancy on the Supreme Court.)