Here's some background on what the American soldiers who came upon [I generally avoided the word "liberation"] Ohrdruf camp.
Gen. Eisenhower was one of them and his comments upon seeing the camp are well known. "We are told that the American soldier does not know what he is fighting for. Now, at least, he will know what he is fighting against."
For a short film of what the Americans, Obama's uncle among them, saw see here
The camp wasn't an Auschwitz but remember, American soldiers had nothing to compare it to, i.e. they couldn't say, "Oh this isn't nice but we know Auschwitz was worse."
I went to some of the Republican blogs and some of the comments are really vicious. [Adam Holland links to them.]