'He is a great American hero and an extraordinary leader. This is why I am endorsing him to be our next president of the United States,' Schwarzenegger (left) said of McCain. -- PHOTO: AP

'He is a great American hero and an extraordinary leader. This is why I am endorsing him to be our next president of the United States,' the actor-turned-politician said on Thursday.

California is the largest prize among the 24 states that hold nominating contests on 'Super Tuesday', Feb 5. Mr McCain, the Republican front-runner, already leads state polls over former Massachusetts Governor Mitt Romney.

Republicans and Democrats are involved in a state-by-state contest to choose their candidates for the November general election to succeed President George W. Bush.

The two Democratic rivals, Mrs Hillary Clinton and Mr Barack Obama, were also in California on Thursday ahead of an evening debate that will pit them alone against each other after former North Carolina Senator John Edwards pulled out of the race on Wednesday.

Campaigning in the heavily Hispanic east side of Los Angeles, Mr Obama touted his work as a community organiser in an attempt to win over a crucial Democratic constituency that currently favours Mrs Clinton.

VIDEO Schwarzenegger endorses McCain (1:59)

'Over the past few weeks we've heard some cynical talk about how black folks and white folks and Latinos cannot come together,' said the Illinois senator, who would be the first black president. 'I take it seriously, because I'm reminded of the Latino brothers and sisters that I worked alongside on the streets of Chicago more than two decades ago.'

Obama aides, meanwhile, said they had raised US$32 million (S$43 million) in January, a huge funding haul that they said would enable them to compete in a drawn-out race.

Mrs Clinton, a New York senator and former first lady, has not yet released her January fund-raising figures.

Romney brushes off endorsements
Campaigning in Long Beach, California, Mr Romney touted his business acumen and said he was not surprised that Mr Schwarzenegger backed Mr McCain.

'We've got endorsements and he's got endorsements,' the former Massachusetts governor and venture capitalist said. 'I think in most cases people make up their own mind.'

Mr Schwarzenegger, a centrist Republican in a state that has voted Democratic in recent presidential elections, praised Mr McCain's ability to work with both Democrats and Republicans.

Mr Schwarzenegger appeared with Mr McCain and former New York Mayor Rudy Giuliani - who dropped out of the race on Wednesday and backed Mr McCain - at a solar panel factory, a site picked to draw attention to Mr McCain's argument that global warming is a challenge that must be addressed.

Mr McCain is more popular among independents and moderate Republicans, who make up a large share of California's electorate, but his strength among traditional conservative Republicans is still a question of debate.

Mr McCain said he believed he could unite Republicans.

'We need all parts of our party together if we're going to win in November. I believe our party is beginning to realise that,' he said.

Another Republican big-state governor, Mr Rick Perry of Texas, endorsed Mr McCain as well.

Candidates are required by midnight (1pm Singapore time on Friday) to reveal fundraising totals for the last three months of 2007, which should give a snapshot of their financial strength before state-by-state voting began.

Republicans have trailed top Democratic candidates in fundraising so far, but Mr Romney has not hesitated to draw on the US$250 million fortune he amassed in his business career. -- REUTERS