Caddies tend to be a faintly eccentric bunch. After all, who in their right mind wants to spend their life lugging a heavy set of golf clubs over their shoulder? In the case of Tom Watson’s caddie, that eccentricity is writ large.

Neil Oxman, 58 and Watson’s bagman of more than 50 tournaments, is probably not your typical caddie. A political consultant from Philadelphia, when Oxman is not heaving Watson’s clubs around a windy Scottish links, he is masterminding the campaigns of mayoral candidates and other public luminaries in his home state of Pennsylvania.

Balding, bespectacled, overweight and known for his fairly crumpled dress — including wrinkled, un-ironed shirts — Oxman resembles what he very nearly is: a dotty Harvard professor with his mind on higher things. He and Watson make for quite a pair as they amble down the fairway.

Yesterday, as Oxman hoisted Watson’s clubs on to Turnberry’s 1st tee for the final round, his head was still spinning at the excitement the two friends have generated at the 138th Open.

“It is a gigantic story and it’s wonderful to see [Tom] playing so well,” Oxman said. “He’s playing wonderfully and I’m just toting the bag. I’m just here to be the support.”

That piece of self-deprecation did not tell the whole truth. Caddies in professional golf, while known for enjoying their après-ski, have to be fairly meticulous by day, mapping out the yardages and humps and hollows of every course to be able to answer their masters’ questions in the heat of competition.

Oxman and Watson, who spend their free time reading The New York Times and The Washington Post online, are no slouches when it comes to their planning, though Watson does not expect his bagman to be out pounding the fairways like a 25-year-old in preparation.

“We are good friends and have been for quite some time,” Watson said of his amiable sidekick. In fact, they became friends in 1972, when Watson was just starting out in professional golf and Oxman was caddying to help pay his way through Duquesne University’s law school.

Oxman’s political leaning is distinctly Democrat. Watson started out in life as a liberal and a Democrat but, by his own admission, has become conservative and Republican as he has got older. The two men often talk about politics as they go about their business.

“I’m a great believer in the truism that, if you are not liberal when you are 19, there is something wrong with your heart, and that if you are not conservative when you are 40, then there is something wrong with your head,” Watson said.

Not even these two, though, could have imagined the stir they have created at Turnberry over these past four days.