In effect the US did stop the Holocaust. By aiding the Allied victory, in defeating Germany, the Holocaust was stopped. If the US could have stopped it sooner, it is possible that they could have, but at great cost.
It is very likely. You could ask a local synagogue tactfully.
The Holocaust was not the fault of the US! It is sometimes said that the US and their Allies did not do much (or anything) to stop the Holocaust. See the related question.
They talk about the holocaust?
Not at all. If you are looking for a comparison with apartheid; you could look at the US treatment of Orientals from the end of the ninteenth century. If you are looking for a comparison to the Holocaust of WW2 Germany, you could look at the US treatment of Native Americans from the 17th century into the 20th century.
The US Constitution was not affected by Holocaust.
well the Holocaust is important to the worlds history.
One cannot say seventy years later what should have happened: The US did what it could at the time.
The Holocaust did not and could not attack people.
You could argue that the Holocaust was the start of the modernity.
no
Nothing specific, the US was fighting a war for most of the time during the Holocaust.