Because I grew up hearing the question, "What would you have done if you lived in Nazi Germany?"
We're not in Nazi Germany, and I don't think we're headed there, but there is great risk of at least mini-pogroms here.
Just look at students at Berkeley beating a pinata while someone with a bullhorn chants" Kill the Jew." Or the violent attack in L.A. on people viewing video footage of Hamas's terrorist attack.
We should all speak up now, before it is too late for speech to be effective.
At the same time, I will stand for the right of Palestinian sympathizers to make their voices heard. There are reports of universities moving to shut down pro-Palestinian groups. That is unacceptable, unless the groups have gone beyond protected speech and have been violent, or threatened Jewish students, or committed significant vandalism and cannot be kept to proper limits through normal disciplinary action. They have a right to their voice criticizing Israel, just not a right to targeting people because they are Jewish.
It's a tragedy that there is too little ability to live in tolerance with each other in the Middle East. But the ideal of America, that all can, and must, live in tolerance with each other here, must be defended and upheld.