Robert Johnson, a lifelong Democrat and the US's first black billionaire, has assessed the Democratic contenders for next year's presidential election. And he doesn't like what he sees.

"If you take a snapshot today, I don't think that group is capable of beating Donald Trump, despite what the polls say," Mr Johnson, the founder of Black Entertainment Television (BET), told CNBC in an interview.

"I think the president has always been in a position where it's his to lose."

Despite his politics, Mr Johnson has praised the Trump economy, particularly a rise in African- American employment, though it remains lower than white employment rates. And he has sided with many conservatives, including Mr Trump, in saying that Democratic politicians have moved too far to the left of American politics.

He told CNBC he sees a "double effect" of Mr Trump's incendiary comments and rhetoric that fires up his base.

Democrats react strongly, he said, which puts the president's supporters on defence and adds to his support.

"I do not see anybody in the Democratic primary race today that is enough in the centre where I believe most are the voters are, and particularly where most African Americans are," Mr Johnson told CNBC.

Mr Johnson sold BET to Viacom in 2001, and later founded an asset management firm called RLJ Companies. His wealth has drawn criticism from activists who say he is out of touch with many African-Americans when it comes to their access to wealth and opportunity.

"Bob Johnson is not working class. He does not reflect the issue, nor does he even seem like he has the ability to speak to the issues of the working cl****" Tosha Brown, co-founder of Black Voters Matter, an organisation focused on increasing black voter turnout, told 'The Washington Post' in July.

Adrianne Shropshire, executive director of the Black Pac, a group working to increase black Americans' political engagement, said that policies proposed by the current field of Democratic contenders are aligned with black constituents.

"So while Mr. Johnson may share the interests of millionaires and billionaires, he's out of step with black voters," she said. Mr Trump has sought Mr Johnson's counsel on engaging with black voters, Mr Johnson revealed after the 2016 election.

He also said Mr Trump hinted at a possible Cabinet position, but he said it was not for him.

"As an entrepreneur trying to work in a government structure where you got to go through 15 layers of decision-making to get what you want done doesn't fit my mould," he said.