50 leading CEOs and politicians were asked if Donald Trump had a 50% chance of winning the election - just 5 people raised their hand

As head coach at global advertising agency group Publicis Groupe, Kevin Roberts travels the world advising brands, sports teams, students, and politicians on how to be better leaders.

On one such recent occasion, Roberts was speaking at a summit in Warsaw, attended by global CEOs, editors of newspapers and magazines, and leading finance and defense ministers from across Europe and the US.

At one session - a discussion about what was needed post-Brexit to move Europe forward - the 50 or so people in the room were asked: Do you think Donald Trump has at least a 50% chance of winning the US presidential election?

Only around five people, including Roberts, raised their hand.

Roberts told Business Insider: "I just said: There you all go again, guys. There are only two people in the race, so he's bound to have at least a 50% chance. You don't have to run faster than the bear - you have to run faster than your mate."

He added: "Denial is not just a river in Egypt. You're Brexiting all over again."

(Ahead of the referendum, most political leaders - even those campaigning for Britain to leave the EU - did not believe Britain would vote for a Brexit.)

RealClearPolitics, which pulls together an average of the available and reliable US polling data, shows Democratic presidential hopeful Hillary Clinton currently has just a 2.7 point lead over Trump.

Clinton is "bereft of a dream" and needs a better selling line

Roberts, who is also the chairman of Publicis advertising agency Saatchi & Saatchi - a firm famous for its emotive Conservative Party election campaigns and where he has worked since 1997 - said Trump has two clear things going for him, which are winning over the hearts of many American voters.

Firstly, he has an easy to understand dream: To "Make America Great Again."

And secondly, he appeals to a sense of human loss.

Roberts said: "We fear loss much more than we look forward to benefit and he's appealing to the great losses: You're losing your women, your jobs, you're losing your country."

Meanwhile, Roberts thinks Clinton is "bereft of a selling line and she is bereft of a dream."

Roberts said: "If you're supporting change and supporting being pissed off and you go down the pub, you can say to your mate: 'We are going to make America great again,' your mate is going [Roberts cheers and bangs the table]: 'Yeah! Yeah!'"

"Mrs Clinton is going: 'We're going to bring government back, have better management, have healthcare. I'm going to improve this, I'm going to improve that, I'm going to tax this' - they don't care."

In 1979, Saatchi & Saatchi created an iconic Conservative Party poster in the run-up to the general election. Labour was in government at the time - a period in which the unemployment rate was high.

The poster read: "LABOUR ISN'T WORKING" and depicted a long, meandering queue outside an unemployment office. Underneath were the words: "BRITAIN'S BETTER OFF WITH THE CONSERVATIVES."

It was viewed as being one of the defining ads that helped the Conservatives win the election, placing Margaret Thatcher as the country's Prime Minister. UK advertising trade magazine Campaign crowned it "the poster ad of the century."

Roberts said: "With 'Labour Isn't Working,' the sense of loss was there - we are all going to lose our jobs - and it was an easy thing to remember."

He thinks Clinton should repeat something similar.

"If Mrs Clinton had a simple dream - to make America a harmonious society, for instance - do we want harmony, or don't we? Yes, I think we all do. Perhaps if she said something like that, she would appeal to that sense of loss," Roberts said.

We asked whether that could backfire, because people are becoming tired of negativity in politics.

"I think people jump to the negativity conclusion. My experience is that people are pissed off with negativity too. Simplicity and finding a sense of loss are the way in."

Clinton's campaign should also focus its efforts on getting people to the polling stations, Roberts said, remarking that the complex state-by-state electoral college system in the US may dissuade some potential voters from bothering.

"A lot of people will say: 'We are not going to bother because it does not make a difference [in our state].' But I don't think [Trump's] supporters will say that," Roberts said. "In the end, one thing we learned about the Thatcher campaign at Saatchi was that it is about getting people to vote that matters."