"It's no secret that that AIPAC has worked to hinder diplomatic efforts like the Iran deal, is undermining Palestinian self-determination, and inviting figures actively involved in human rights violations to its stage," said Iram Ali, campaign director at MoveOn Political Action, in a statement to Politico. Ali also said the call should "give a clear insight to 2020 candidates on where their base stands instead of prioritizing lobbying groups and policy people who rarely step outside of D.C."

So far, no candidates have said whether they will attend or boycott the conference, which begins this Sunday. But Speaker of the House Nancy Pelosi (D., Calif.), Senate Minority Leader Chuck Schumer (D., N.Y.) and House Majority Leader Steny Hoyer (D., Md.) are scheduled to appear at the conference, along with Israeli Prime Minister Benjamin Netanyahu and many Republican lawmakers.