US:Republican frontrunner John McCain has received a fresh boost ahead of Super Tuesday with the endorsement of California governor Arnold Schwarzenegger, who described him as a leader who could work with political opponents to get things done, writes Denis Stauntonin Los Angeles
"He's a great American hero and an extraordinary leader," the governor said.
Mr McCain predicted a flood of further endorsements over the next few days as he seeks to consolidate his lead before more than 20 states hold primaries and caucuses next Tuesday.
"I won a Republican-only primary in the state of Florida but I also have been able to gain the support of independents, as well, which is vital to winning a national election," he said.
Mr Schwarzenenegger's endorsement came hours after a Republican candidates' debate that saw bitter clashes over Iraq and the economy between Mr McCain and his strongest rival, former Massachusetts governor Mitt Romney.
Within minutes of taking his seat on the stage at the Ronald Reagan presidential library in California's Simi Valley, Mr Romney declared that Mr McCain's views on immigration, campaign finance reform and global warming put the Arizona senator outside the conservative Republican mainstream.
"I'd also add that if you get endorsed by the New York Times, you're probably not a conservative," Mr Romney said.
Mr McCain noted that he had also received endorsements from newspapers in Mr Romney's home town of Boston before condemning his rival's record as Massachusetts governor.
Mr McCain said that Mr Romney raised taxes while calling them fees and saddled his state with a $240 million debt after introducing a new health care system.
After a lengthy defence of his record, Mr Romney accused Mr McCain of employing "dirty tricks" by misrepresenting his record on the Iraq war.
Mr McCain claimed before this week's Florida primary that his opponent favoured a timetable for withdrawal from Iraq last year, pointing to an interview in which Mr Romney said that president George Bush should talk to the Iraqi government about "timetables and milestones" but should not make them public.
"I do not propose, nor have I ever proposed, a public or secret date for withdrawal.
"It's just simply wrong. And by the way, raising it a few days before the Florida primary, when there was very little time for me to correct the record . . . sort of falls in the kind of dirty tricks that I think Ronald Reagan would have found reprehensible," Mr Romney said.
Along with Mr McCain and Mr Romney, the debate included former Arkansas governor Mike Huckabee and Ron Paul, a US House member from Texas.
The withdrawal of Rudy Giuliani, who endorsed Mr McCain just before the debate, has left four candidates in the Republican race but Mr Huckabee and Mr Paul struggled to make their voices heard amid the two-way battle between the frontrunners.
Mr Paul said that the dispute over who said what about Iraq was a trivial distraction from the fundamental questions Republicans should ask about American foreign policy.
"We have a foreign policy where we blow up bridges overseas and then we tax the people to go over and rebuild the bridges overseas and our bridges are falling down and our infrastructure is falling down," Mr Paul said.
Mr McCain is ahead in most of the big states that vote next Tuesday but Mr Romney hopes that the deep antipathy many conservatives feel towards the Arizona senator will help him to win in the south, the west and the midwest.
Mr Huckabee's decision to remain in the race could hamper Mr Romney by siphoning away conservative votes, particularly in the south.
Unlike their Democratic counterparts, many Republican primaries award a state's entire delegation to the candidate who wins most votes, so that victories in the most populous states could give Mr McCain a decisive lead.
The withdrawal of Mr Giuliani and of Democratic candidate John Edwards has set off a scramble for their fundraisers and contributors among surviving campaigns.
The race for cash is especially intense on the Democratic side, with Barack Obama's campaign saying he raised a record $32 million in January alone.