From the Labour leadership debate reported in Guardian,

"Labour has been too slow to admit that the party has a problem with antisemitism – something it should be ashamed of, Smith says. "How has this happened?" he asks Corbyn.

Corbyn says many of the cases pre-date his leadership and wants Labour to be inclusive. "
http://www.theguardian.com/politics/live/2016/aug/04/labour-leadership-debate-jeremy-corbyn-and-owen-smith-in-cardiff-live?page=
There you go Steve.
They both acknowledge that Labour has a long standing "problem with antisemitism."

Why would anyone dismiss what they say and listen to you?