MARJAH, Afghanistan – When I came to Afghanistan, I expected to find many strange and unusual sights. A gunnery sergeant with a tattoo of Sarah Palin on his buttocks wasn’t one of them. So it is, however. Within minutes of meeting Marines who patrol this former Taliban stronghold from the Yellow Schoolhouse, a rundown former Afghan school here, I was asked my opinion about Palin, a hero to many politically conservative Americans. Before I had a chance to answer, however, I was introduced to fun-loving Gunnery Sgt. Benjamin Lepping’s left butt cheek. Sure enough, there’s a realistic caricature of Palin…