What is Anti-Semitism?

Anti-Semitism is:

• A designation used to describe ideas rooted in the intent, or that have the effect of, disenfranchising Jews. This is often characterized by applying standards to Jews that are not applied to other people or groups when they can be, or ignoring them when found among other people or groups.
• Denying or falsifying Jewish history with the intent of disenfranchising Jews.
• Ascribing to the perspective that Jews secretly collaborate, and deny attempts to, infiltrate, manipulate, and influence a society’s ideas or values as a means to exercise control over political processes. Charging Jews with an unfounded lack of loyalty to their country of citizenship is an expression of this perspective.
• Ascribing to the perspective that the nature of being Jewish is financial greed, immorality, perversion, and sinfulness.

Anti-Semitism is not:

Any criticism of Jews or Israel in a manner consistent with criticizing other parties and based on the same or similar principles. For example, criticizing an Israel lobby is not Anti‑Semitic if one understands that lobbies are designed by nature to exert influence or control over political processes. It is perfectly reasonable and just to criticize an Israel lobby in this manner. Another example: claiming that the Jews run Hollywood if one considers that the role of Jews in Hollywood is not reflective of the entirety of American Jewry.

Don't Meet the Neighbors

The concept of being influenced by the people around you and the society in which you live is a recurring theme in the Torah. Perhaps the first example of this is found in parasha Vayera where Avraham pleads on behalf of Sodom. The sinful nature of that community prevented the development of any righteous people, save for perhaps Lot and his nuclear family.

And Abraham approached and said, 'Will You even destroy the righteous with the wicked? Perhaps there are fifty righteous men in the midst of the city; will You even destroy and not forgive the place for the sake of the fifty righteous men who are in its midst? Far be it from You to do a thing such as this, to put to death the righteous with the wicked so that the righteous should be like the wicked. Far be it from You! Will the Judge of the entire earth not perform justice?" And the Lord said, "If I find in Sodom fifty righteous men within the city, I will forgive the entire place for their sake.'" (Genesis 18:23-26)

Even after Avraham's heartfelt and eloquent beseeching to God on behalf of a community that probably didn't deserve it, alas it seems that it had fallen below the "unredeemable" threshold and was destined for destruction.

This theme is also active in the parsha of Korach, in which the jealous and zealous Levitical scholar mastermind managed to recruit a hefty 250 rabbinical authorities to confront Moshe Rabbeinu and (im)politely ask him to relinquish his position as head prophet.

Dothan and Aviram, who were not Levites, but from the tribe of Reuven, were among the people pulled into this rebellion. Rashi explains that the geographical proximity of their encampment to Korach's was the main reason for their aquiesence:

Since the tribe of Reuben was settled in the south when they camped, thus being neighbors of Kohath and his children who were also camped in the south, they joined with Korah in his rebellion. Woe to the wicked, and woe to his neighbor! (Numbers 16:1)

They should have run like Forrest.