Hispanic voters in Florida are set to reject Bernie Sanders when the state goes to the polls in the race to elect the Democrat presidential nominee on Tuesday.

Mr Sanders' campaign, which has touted his support among Hispanic voters, hoped their backing nationally would help offset Joe Biden's lead among older white Democrats.

Mr Sanders won 51 per cent of Hispanic voters when he triumphed in Nevada, with only 13 per cent supporting his rival. But a poll in Florida showed Mr Biden winning 48 per cent of Hispanic Democrats to 37 per cent for Mr Sanders.

Florida is home to a large number of exiles from Cuba and other soicialist Latin American countries including Venezuela and Nicaragua.

Mr Sanders – who describes himself as a democratic socialist – damaged his chances when he was reluctant to declare Venezuela's Nicolas Maduro a "dictator," and when he said Fidel Castro had improved literacy rates in Cuba.

Giancarlo Sopo, a political analyst, said: "The Hispanic voters of Florida are very familiar with Latin American socialist extremism, and clearly see in Bernie Sanders a candidate who favours these regimes."

Carmen Pelaez, 48, a Democrat Cuban-American in Miami, said: "Why is he staying in [the race]? For the four votes he's going to get in Florida?

"He has always said good things about the Latin American dictators. That tells me that he doesn't see our humanity the same way as he sees the humanity of the Americans."

The latest polls showed Mr Biden with an overall lead of around 40 percentage points in Florida.

A candidate needs to amass 1,991 delegates through the state-by-state voting process to win the presidential nomination. Mr Sanders currently trails Mr Biden by around 150 delegates.

Florida, one of the most populous states, awards 248 delegates. Ohio, Illinois and Arizona also vote on Tuesday, and Mr Biden leads in polls in all of them.

Mr Sanders was faring slightly better among Hispanic voters in Arizona, but still held only a narrow lead over Mr Biden. A Univision poll showed 44 percent of Democrat Hispanic voters in the state favoured Mr Sanders, with 39 per cent backing Mr Biden.

Among all Democrat voters in the state, Mr Biden had a lead of 51 per cent to 34 per cent.

Mr Sanders' campaign had suggested that he was best positioned to spark record turnout among America's quickly rising, and Democrat-leaning, Hispanic population in the presidential election against Donald Trump in November.

It was argued that would have a particular effect in states such as Arizona along the Mexico border, where Mr Trump has pledged to build a wall.

Polls show that Hispanic voters in Arizona overwhelmingly oppose the border wall and that virtually all Mr Sanders' supporters would be prepared to switch their allegiance to Mr Biden if he becomes the Democrat nominee against Mr Trump.