Is J Street "anti-Israel"?

While writing a previous post about a column by Caroline Glick in The Jerusalem Post I could not help but notice how she denounced J Street as a "Jewish anti-Israel organization".

Jewish anti-Israel organizations such as J Street, Open Hillel and the New Israel Fund in the US, and European governments and government- funded organizations in Europe have operated largely free from criticism by official Israeli voices unwilling to take sides in the debate about the country’s right to exist and defend itself. (Caroline Glick, The New Government's War on BDS, Jerusalem Post, June 4, 2015.) 

J Street is "anti-Israel"? How can that be? It is an organization mainly composed of Jews. What is going on here?

Maybe we should take a look at the other side of this story. To compare Glick's comment let us compare it with the following column by Chemi Shelev, a columnist for Haaretz.

Now it’s J Street, which one way or another represents a sizeable chunk of American Jewry, that is first barred from joining the Conference of Presidents and is now being denounced for daring to buck the line adopted by much of the organized establishment in connection to the Iran deal. The fact that J-Street seems to be reflecting the opinion of a majority American Jews, mind you, makes no impression on the group’s detractors.

Together with J-Street in the right-wing’s rogues gallery is the perennial favorite, the New Israel Fund (NIF) - a bunch of idealistic Jewish do-gooders if I ever saw one - which is repeatedly defamed, maligned and falsely accused of supporting the Boycott, Sanctions and Divestment (BDS) movement. NIF is so toxic that its poison apparently spreads to anyone who happens to support it or come in contact with it.... (Chemi Shelev, 10 Comments on Mike Huckabee and the Purveyors of Jewish Hate-porn, Haaretz, July 28, 2015.)

Based on these words by Shelev it would appear that J Street is viewed with disdain by many right wingers. So to call J Street "anti-Israel" appears to be partisan rhetoric by right wingers against left wingers rather than an accurate description of J Street.