I know you're just trying to account for a ridiculous position. But the question remains "Why do Americans feel guilty about Auschwitz?" Why, when they do not feel guilty about far worse things for which they bear far more direct responsibility? My answer is that the guilt (assuming there's any) has been drummed into them through repeated exposure to the zionist version of WWII: the only people who were involved in the Holocaust were jews; the US went in to liberate them; the sufferings of the jews were unique in human history; arabs hate jews and they must be made to pay for this. Every single statement here is a lie, and these lies have been repeated constantly for the last fifty years.
This may account for the alleged American guilt about the jews. But alleged or not, it is not the guilt that drives the policy but the other way around.
Joanna