The self-declared mission of J Street, the dovish "pro-Israel, pro-Peace" lobby that just concluded its first national conference this week, includes redefining the meaning of the term "pro-Israel." For too long, the organization's founders and supporters argue, right-wing elements in the Jewish community have abused the term to hijack the debate and tarnish mainstream, sensible advocates of a two-state solution.

J Street's "pro-Israel" bona fides were questioned almost immediately after its launch, and with good reason. For starters, the organization took needlessly provocative stands, like backing the decision to stage the play, Seven Jewish Children, which compares the suffering of Jewish youth under Nazi Germany to that of Palestinians in the...