There is a video clip here of President Obama signing the vistors' book at Yad Vashem. You might want to start three minutes in, as that is when he begins speaking. One of the things he says early on is this:
We have come here a thousand times and each time our hearts would break.
A single sentence constituting, all on its own, a total response to those who say there's too much attention given to, too much said about, the Holocaust (on which see this normblog series). Obama's few words that I quote above are the elementary response of any feeling human being whose head has not been stuffed with ideological nonsense of one kind or another.