If a week is a long time in politics, 18 months is an eternity. In autumn 2008, the then Republican presidential nominee John McCain stunningly plucked Sarah Palin from Alaskan obscurity, launching her on a national political career and giving her the chance to make millions as an author and cable TV star.
Yesterday and again today Ms Palin, who also happens to be among the leading contenders for the 2012 Republican presidential nomination, is making a small return for those very considerable favours. She is stumping alongside her benefactor in Arizona, as he faces the toughest home-state re-election fight of his long career.
This time their reunion will be relatively brief, but one that rekindles many memories. After holding a rally in Arizona's second city of Tucson yesterday, they return to Phoenix today for more events, among them a fundraiser in the same Biltmore hotel where Mr McCain delivered his gracious and generous concession speech on the evening of 4 November 2008.
Since then both the man and American politics have been transformed. The old McCain, often ready to work across the aisle with Democrats, beloved of reporters for his frankness and readiness to buck the conventional wisdom, has seemingly turned into a mean-spirited grump – whose most notable declaration of late has been that after passage of the healthcare legislation, there will be "no co-operation for the rest of the year".
But an even bigger change has taken place in Republican politics, in Arizona and elsewhere. Elected to the first of four Senate terms in 1986, Mr McCain's seat had been a virtual sinecure. In 1998 and 2004, he was unopposed in the party primary, before winning re-election in the general election by margins of up to 70 per cent.
But now, as he seeks a fifth term at the age of 73, the future suddenly looks much less certain. Mr McCain is facing a predicament increasingly common for Republicans deemed too moderate by party hardliners: a primary challenger from the right, backed by the insurgent Tea Party movement.
In Mr McCain's case that predicament bears the name of J D Hayworth, once a Congressman and until recently a radio host, a 6ft 5in-tall showman who bills himself the "consistent conservative". For a while, Mr McCain ran 15 or 20 points ahead but, according to a recent poll, that margin has shrunk to five points. The unthinkable is now a possibility: that Arizona's old lion, its most famous political son since Barry Goldwater, could lose.
So Mr McCain has brought in his old running mate – now the darling of the angry, "real" conservatives whose voices are loudest in the contemporary Republican party, and favourite figurehead of the Tea Partiers – to help bring wavering conservatives back into the fold. And the lady has obliged. "Everyone here supporting John McCain, we are all part of that tea party movement," Palin told the rally.
As the former Alaska governor and McCain took the stage, the crowd chanted, "Sarah, Sarah," not the name of the man who just a year and a half ago topped his party's ticket.
Palin said McCain warned the country that Obama's policies would increase the size of government and the debt, and that the signing this week of a health overhaul law proves McCain right.
Palin said the Republican Party needed new blood and new leaders, "but we also need statesmen and heroes like John McCain in there to help us get through these challenging times."
"In 2008, I firmly believed that John McCain was the right man for America. Today, I know he's the right man for Arizona," she wrote in The Arizona Republic paper yesterday. "Your state deserves more than rhetoric; you deserve a leader with a real record of accomplishment."
That endorsement may, however, not be as ringing as it sounds: the pair have barely spoken since the race for the White House, and Ms Palin's reputation has been shredded in books chronicling the contest. To be fair, the most devastating criticism has come not from Mr McCain himself but from his top lieutenants, and from staffers seconded to the Palin team following her shock selection as running mate. Much of it found its way into the pages of the best-selling Game Change, the gossipy account of the campaign by the political journalists John Heilemann and Mark Halperin.
This weekend, these slights will go unmentioned. Indeed, Ms Palin's mind may be on her latest media coup – she will host a reality-cum-documentary TV series about her home state. Deep down, her loyalties may lie more with Mr Hayworth than with her old campaign partner.
J D Hayworth: The radio rival
J D Hayworth – the man standing between John McCain and a fifth US Senate term – is no newcomer to politics, having already spent 12 years in Congress. A former sportscaster, he could be heard on the conservative radio station KFYI until recently, but resigned as a talk-show host when McCain's team complained that Hayworth was using his slot to campaign. Earlier this month Hayworth claimed in a radio interview that laws allowing gay marriage could result in people and horses getting married. It is not the first time his comments have caused controversy – in 1998, he called President Clinton an "unprincipled philandering President".