Rebecca Tyrrel: 'Could allegations of canine cruelty become a major election issue for Mitt Romney'?

Who knew that Mitt Romney once drove for 12 hours to a holiday in Canada with the family dog on the roof of his car? And who knows how this might affect his chances of winning the US presidency if he wins the Republican nomination next year and the allegations of canine cruelty become a major election issue?

Since the journey was made in 1983, the dog in question, an Irish setter called Seamus, is no longer around to bear witness. But the facts, undisputed by the devout though monogamous Mormon, are these. Short of space with a wife and five sons to fit into the car, he placed the dog in a 'carrier' and strapped it to the roof rack.

What is strongly disputed is how Seamus felt. Romney has claimed that the dog was more than happy about it. "He scrambled up there every time we went on trips. They're [animal rights protesters] not happy because my dog liked fresh air."

Others disagree, citing Seamus's perhaps predictable reaction to this scary exposure to the elements as evidence of distress. A few hours into the journey, one of the Romney boys yelled, "Uurrgh Dad... gross!" as a brown rivulet flowed down from the roof and over one of the rear windows. Romney calmly pulled into the next service station, borrowed a hose, and cleaned both dog and windows together, which I suppose shows a certain executive competence.

Since Romney's current main rival for the nomination, the Texas governor Rick Perry, has a thing about executing prisoners, including the apparently innocent, the shaggy-dog tale might seem small fry in the Republican tough-love stakes. It may even help Romney, widely criticised for introducing a healthcare scheme when governor of Massachusetts, by revealing a heartless side which the Party would relish.

Romney has other electoral worries, notably his religion, and when added to a canine controversy certain to explode if he wins the nomination, you have to fear for his chances.

With the inevitable rows about financial scandals and religious faith, US elections are heavily influenced by God and Mammon. For Mitt Romney, it may all boil down to dog and Mormon.