No, J Street is not "pro Israel". It's a extrem leftist organization, financed partially by George Soros, by pro-Arab and pro-Iran groups and they know why they are spending their money. J Street has many friends in the Obama administration, but the J Streetlewrs are not just "dovish Jews", they are enemies of Israel, even if it sounds to somebody too extreme.
Shaffir to Herzog: Opposition failed to show leadership in political battles against PM (Haaretz)
from the article: Dovish Jews? They love Israel? Excommunicate them