Republican Presidential Candidates May Generate Less Heat At Miami Debate

Republican presidential candidates may find themselves in a more subdued debate than usual on Thursday night in Miami, since nothing Donald Trump's rivals have thrown at him has made a major dent in his front-running campaign.

After the histrionics of last week's gathering in Detroit, the four remaining candidates are likely to search for higher ground as they offer closing arguments to Republican voters, particularly those in Florida and Ohio, who vote next Tuesday in nominating contests for the November 8 election.

The burden is particularly heavy on US Senator Marco Rubio of Florida and Ohio Governor John Kasich, who must do well in their home states or face pressure to exit the race.

While Kasich is holding his own against Trump in Ohio opinion polls, Rubio has lagged far behind Trump in Florida.

Trump's victories in Michigan, Mississippi and Hawaii on Tuesday added to his momentum after a week of attacks by mainstream Republicans who are offended by his statements on Muslims, women and illegal immigrants and alarmed by his threats to international trade deals.

A supporter raises his hand as Republican US presidential candidate Ted Cruz speaks at a campaign rally in Miami on March 9, 2016. (Reuters photo)

The tough-talking billionaire businessman told CNN on Wednesday he expected the debate to be a "nicer, softer, lighter debate, I hope." But he added: "I'll be ready.

I'm the only one who can beat Hillary," a reference to Democratic presidential front-runner Hillary Clinton.

The tone could be set by Trump, 69, who forecast before several previous debates that he would take a more measured approach, only to quickly get into a verbal brawl with his rivals.

The CNN-hosted debate will be held at the University of Miami at 8:30 pm. (0130 GMT on Friday).

"I would focus on a positive uplifting message that takes us back to why they're running for president and what's at stake in this election," said Eric Fehrnstrom, a senior adviser to 2012 Republican nominee Mitt Romney.

In Detroit last Thursday, Trump came under sustained fire from Rubio, 44, over parts of his business empire such as Trump University, a now-defunct venture that critics said offered a flimsy education. U.S. Senator Ted Cruz of Texas piled on Trump over his past support for Democratic causes.

Trump blasted Rubio throughout the debate as a lightweight and Cruz as a liar.

'Kids embarrassed'

The Trump-Rubio debate clash in Detroit followed an abrupt change in Rubio's campaign to begin raising personal questions about Trump, such as saying he had small hands, a statement Trump saw as a reference to his penis size.

Rubio said he now regretted the personal insults.

Republican US presidential candidate Senator Marco Rubio pauses while addressing supporters during a campaign rally in Sarasota, Florida on March 8, 2016. (Reuters photo)