NOTHING says Christmas like the Iowa caucus. Going to church, unwrapping presents and eating turkey on Christmas Day will be one big photo-opportunity for the presidential candidates who face their first crucial test at the polls on January 3.

Iowa’s determination to preserve its status by holding its caucus earlier than ever has turned the season into one of forced jollity, with the Republican and Democratic candidates competing for the cheesiest advertisements and pretending to be enjoying a fun-packed holiday with their families.

The week before the vote isa traditional time for phone calls, direct mail, big rallies and sharpened attacks on rivals, although candidates are terrified of offending voters by interrupting their Christmas dinners with an “important phone message” from the likes of Hil-lary Clinton or Mitt Romney.

Most candidates are dashing home to be with their families, although the private planes – for those who can afford them – will be turning around almost immediately so they can rejoin the campaign trail. “I’ll be back on the 26th and I’ll just continue blitzing the state,” Clinton promised last week.

One candidate, Chris Dodd, will stay in place. He moved his family temporarily to Iowa and will celebrate Christmas there, although he remains a no-hoper for the Democratic nomination.

Barack Obama’s campaign plans to “dim the lights” at Christmas, but will still be operating. “It’s tricky,” said David Axelrod, Obama’s top strategist. “You spend 10 months trying to be Santa Claus and you don’t want to be the Grinch, stealing Christmas and invading people’s privacy. But it’s so close to the caucuses, you can’t avoid talking to people and so I’m sure that we will.”

Obama’s photogenic daughters, Malia, 9, and Sasha, 6, who have hitherto been kept out of sight, appear in the cutest festive TV commercial, wishing voters a “merry Christmas” and “happy holidays”, targeting the religious, the secular and the politically correct.

They appear with their parents in front of a beautifully decorated tree and flickering fire, but a spokesman for the campaign declined to say whether the commercial was filmed in their home or a studio (it looks suspiciously perfect).

Clinton has attracted the most criticism on the right for a “materialist and socialist” television ad in which she doles out presents labelled universal health insurance, alternative energy and universal preK (nursery school). It has already been parodied with the taxpayer’s price tags attached.

Mike Huckabee, the surprise Republican favourite, has been milking his claim to Christian leadership. On Christmas Eve, he will attend church with his family and then go out for a Chinese meal, with television cameras almost certainly in tow.

The most powerful Christian message this season comes not from Huckabee, but from John McCain, who endured several Christmases as a prisoner of war of the North Vietnamese.

One night a prison guard silently loosened the ropes that tormented McCain, the candidate recalls in his commercial. The guard returned on Christmas Day. McCain describes how the guard “rather nonchalantly used his sandalled foot to draw a cross in the dirt. We stood wordlessly looking at the cross, remembering the true light of Christmas, even in the darkness of a Vietnamese prison camp. A minute or two later, he rubbed it out and walked away”.

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