There is a lot of Jewish support for Corbyn. Its just well hidden because they are being prevented from being a voice.
Here's a voice
Why I am an anti-Zionist Jew
Operation Protective Edge, in which over 1900 Palestinians and nearly 70 Israelis have now been killed, is just the most recent, inevitable consequence of a brutal, militaristically-advanced settler-colonial occupation encroaching on the lives and lands of a subjugated people – using a 30-foot wall, settlements, missiles, tanks and the withholding of basic human necessities to perpetrate continued domination. This form of militarism is not specific to Israel – the Islamic State, the treatment of Native Americans in the USA, and South African apartheid bear comparison - but that doesn't make it any more defensible.
While today a majority of observing Jews identify with the state of Israel, there is both a growing and visible minority of anti- and non-Zionist Jews, and a rich history of anti-Zionism within Judaism. Political movements like
The Jewish Labour Bund and thinkers such as Abraham Serfaty,
Emma Goldman and
Leon Trotsky are often ignored or dismissed as “self-hating traitors”. In the UK today groups like Jews for Justice for Palestinians,
Jewdas, Young Jewish Left and the International Jewish Anti-Zionist network are active voices against the occupation.
https://www.opendemocracy.net/transf...ntizionist-jew.
And another