Reuven "Ruby" Rivlin is a principled Zionist, who believes deeply in the People and State of Israel. Since becoming President of  Israel about a year and a half  ago, he has sought to embrace the idea of Israel  as a big tent, composed of  different types of people  believing in a diverse range of ideas and tenets, both religious and  political.

President Rivlin spent much of his Hanukkah holiday visiting the US, with the special purpose of meeting with US President Obama at the White House. But in addition, on December 13, in New York, he delivered the keynote address to the Haaretz Conference held in conjunction with the New Israel Fund.

In doing so, Rivlin has taken the idea of a big tent to the point of self-destructive inclusiveness.

Consider the irony of the President of Israel welcoming members and supporters of a wealthy and powerful fund which donates a significant portion of its contributions to organizations whose mission is to demean, de-legitimize and ultimately to destroy the State of Israel.

Sound incredible? Sadly, it is both incredible and true. Whether it is Breaking the Silence, whose raison d'etre is to accuse the Israel Defense Forces of war crimes, or B'tselem, which seeks to indict the State of Israel with crimes agsinst humanity, or Adallah, which seeks the end of Israel as a Jewish  state, NIF-supported organizations lead the denunciation of Israel from within.

Some of these very groups will be featured as presenters and guests at the conference. But it is doubtful that it will be mentioned that these groups receive most of their funding from European governmental-related NGOs, and even the Palestinian HUMAN RIGHTS AND INTERNATIONAL HUMANITARIAN LAW SECRETARIAT: DENMARK, SWEDEN, SWITZERLAND, AND THE NETHERLANDS Fund.

Of course, the NIF also will not withhold funding from organizations who support the boycott, divestment and sanction of Israel  (BDS), even though it claims to oppose BDS.

So the logical question is, why is President Rivlin doing this? Alas, intelligent, compelling or even sympathetic answers don't quite roll off the  tongue.

One either concludes that the President is bowing to the NIF – a powerful and influential force -  seeking the validation of a Presidential appearance, or he is oblivious to the fact that he is being manipulated.

Either way it doesn't look good for him.

If the former, then we have to  face  up to the challenge of  confronting a powerful organization that has clothed itself in the legitimacy of support for  many innocuous organizations providing needed social services, while simultaneously providing vital support for  many of the most toxic and hateful organizations in Israel.

If the latter, then the defenders of Zion need to be raising their voices louder and louder in making sure that all Israelis, President Rivlin included, are aware of the danger from without and within.

Regardless, we would hope that President Rivlin understands and agrees that supporting a big tent has its limits, and doesn't include supporting those seeking to have the  tent collapse inward upon itself.

The writer is a member of the Board of Directors of Im Tirzu and the Israel Independence Fund.