POLITICIANS are used to being accompanied by bodyguards. Hillary Clinton has an extra shield: a Republican guard protecting her from accusations that she is too left-wing. Her mission to persuade voters that she is centrist enough to become president in 2008 depends on the company she keeps.

Clinton, a Democrat senator for New York, rarely takes a step in public or a policy initiative without being surrounded by Republicans. It is disarming her opponents and helping to polish her image as a moderate with a realistic prospect of winning the White House.

Clinton spent last week in “baked Alaska”, which has been experiencing record high temperatures, to investigate one of the left’s favourite causes, global warming. Her travelling companions were three Republican senators: John McCain, Lindsey Graham and Susan Collins.

Together they agreed, in the words of McCain, that there was “overwhelming scientific evidence” of climate change and that “human activities play a very large role”. All Clinton had to do was concur. It is as if they are “dating”, said one cynical television news anchor.

“Hillary is trying to become less Hillary and more Clinton by following her husband’s path to election as a moderate,” said Kellyanne Conway, a Republican strategist. “It’s a very smart strategy to hang out with McCain because he’s a media darling and it guarantees favourable coverage.”

Clinton visited Iraq earlier this year with McCain — both are against withdrawing American troops on the grounds that greater numbers are needed to assure success — and has joined forces with Graham on improving health insurance for army reservists.

She has co-operated on health reform and national security with right-wing ideologist Newt Gingrich, one of the fiercest opponents of her husband Bill Clinton, and with Bill Frist, the Republican Senate leader. There is a trade-off: her star power generates an enviable level of attention for their initiatives.

Sightings of Clinton with leading Democrats such as John Kerry, last year’s presidential contender, have become rare while Bill is now best friends with George Bush Sr, the former president.

Clinton’s well crafted bipartisanship is beginning to grate with conservatives. Peggy Noonan, Ronald Reagan’s former speechwriter, last week derided the “creepy chumminess” between the two camps.

“Newt smiling with Hillary and John McCain giggling with Hillary leaves you wondering: why are these people laughing?” Noonan complained.

The one Republican who could take centre-left votes from Clinton in a presidential contest is McCain, not least because of his reputation for putting politics above party. Cosying up to Clinton, however, could hurt his chances of winning his party’s nomination in 2008.

“He should be attacking Hillary Clinton if he wants to be popular with Republicans, but he enjoys the attention,” said Larry Sabato, a political analyst at the University of Virginia.

Clinton has the left of her party so sewn up that she can afford to move to the centre without alienating her base. The question remains whether the American public will buy her image as a moderate.

Mike McCurry, White House press secretary for Bill Clinton, said her interest in bipartisanship was genuine. “The country is hungry for any leader who wants to rise above the divisiveness,” he added. “The irony is: she is the least well placed politician to do that because she is a lightning rod for the right.”

Clinton’s moderation is paying dividends in New York, where she faces a battle for re-election to the Senate next year. Polls show her leading Jeanine Pirro, her Republican rival, by 64% to 28%. Clinton has already accumulated a war chest of $21.8m for the race. “She’s raising money at a presidential clip,” said Steven Weiss of the Center for Responsive Politics.

Conservatives in New York are beginning to cold-shoulder Pirro while the tabloid newspapers are having a field day with her husband Al Pirro, a convicted fraudster and father of a 22-year-old illegitimate daughter.

Republicans had been hoping to use the Senate race as a means to turn Clinton into damaged goods before 2008 but she has high approval ratings even in conservative upstate New York. The same is not true for the rest of America. “So far it’s been an easy ride but she has a massive set of problems,” said Sabato. “She is not only seen as a liberal, she is also disliked.”

Nobody knows this better than Clinton herself, according to McCurry. Even if teaming up with the right does not win her the White House, it could help her to maintain a high profile in the Senate for years to come. “I would not be surprised if she were to decide that this was the best contribution she could make to her country,” he said.

Either way, she will be flanked by her Republican guard.