This is oddly passive: "when the Palestine movement actually allows real antisemitism to stand, they end up lending credence to the allegations." Actual antisemitism is the thing itself, not something that "lends credence to allegations". It's not like allegations can be both false and true.

The allegations are that the movement is captured my antisemitism, right?

There is one pair of rules for Israels Advocatedss: 1. deflect from Israeli zionism, Apartheid, crimes 2. make everything about "antisemitism"