MEXICO CITY (AFP) - It featured drama and tension fit for a telenovela: A bouffant-haired, billionaire-turned-politician clashing with a famous TV journalist intent on getting answers.

The jaw-dropping scene played out on 'live' television in August, when White House hopeful Donald Trump threw famous Mexican-American reporter Jorge Ramos out of a news conference.

The anchor for Univision, a US Spanish-language channel, was trying insistently to ask a question about immigration when Mr Trump shot back that the journalist had not been called on.

"Go back to Univision," Mr Trump barked and a security guard escorted Mr Ramos out.

The fracas erupted just two months after the real estate tycoon entered the race for the Republican nomination with harsh words about Mexican immigrants, calling them rapists and vowing to make Mexico pay for a massive border wall.

"We were tremendously wrong to not have confronted him from the beginning," Mr Ramos, 58, told AFP in an interview in Mexico City on Monday.

"Many governments and many media simply did not react to the danger of someone who was attacking migrants, Muslims and women," he said, referring to other controversial comments made by the Republican front runner.

Mr Ramos lamented that the "danger" came from Mr Trump's ability to capitalise on anti-establishment anger in the United States while "allowing racist and discriminatory sentiments, which many thought no longer existed, to surface".

"There's a real demographic revolution in the United States, a revolution in which whites will become minorities in 30 years," Mr Ramos said, referring to the ever-growing Hispanic community, standing now at 17 per cent of the US population.

"So I think that there's resistance among many Americans against seeing their country, accents and colours change."

Mr Ramos, who lives in Miami, considers himself an immigrant even though he has acquired US citizenship.

He crossed the border more than 30 years ago after, according to him, Mexico's powerful Televisa network censured his first report.

Mr Ramos, silver-haired and blue-eyed, became a renowned journalist at Univision, which caters to the estimated 55 million Latinos who live in the United States.

He has anchored the channel's nightly news programme since 1986, attracting 2.5 million viewers.

He also hosts a Sunday talk show, writes a weekly column and, since 2013, leads "America with Jorge Ramos" on Fusion, an English-language channel.

Last year, Time magazine named him on its list of the world's 100 most influential people. Mr Ramos used his acceptance speech to call for the resignation of President Enrique Pena Nieto, but his battles with Mr Trump have garnered more headlines.

Horrified at the prospect of Mr Trump becoming president, Mr Ramos believes in journalism that "takes sides".

Mr Trump said earlier this year that he was willing to accept an interview with the "anchor (not) baby" - a play on words with the phrase "anchor baby", which backers of tougher immigration laws use to refer to children born on US soil to illegal migrants.

But Mr Ramos said Mr Trump has not replied to his interview requests.

"I am ready whenever he's ready to speak, but I think that he knows that it will be a tough, confrontational interview, and he doesn't want that right now," Mr Ramos said, smiling.

Mr Ramos warned that "nobody, absolutely nobody can get to the White House without Latinos (who vote)".

But the star journalist, who is promoting his 12th book, Sin Miedo (Without Fear), downplayed his influence among Hispanics.

"I don't have the power to change a president, I don't have the power to give anybody a visa. Our power, as journalists, is to ask questions and question those who have power," said Mr Ramos, whose new book features interviews with powerful politicians and "rebellious" people.

"A journalist's place is as a counterweight," he said.

While Mr Ramos said that journalists cannot have any political affiliation, he appears somewhat uneasy when asked about his daughter's work for the campaign of Democrat Hillary Clinton.

When he interviewed Mrs Clinton or moderated a Democratic debate, Mr Ramos reminded viewers about his daughter's job in order to show there was "no conflict of interest".