Democratic presidential candidates Hillary Clinton and Sen. Bernie Sanders. (Jewel Samad/AFP/Getty Images)

The only Jewish candidate in the 2016 presidential race, who calls himself "100 percent pro-Israel," and one of Israel's strongest U.S. defenders are nearing a fight over what being a pro-Israel Democrat means.

Sen. Bernie Sanders of Vermont plans to push for revisions in the Democratic Party position about relations with Israel, with a focus on elevating Palestinian rights as a U.S. priority, people involved in discussions over potential changes to the Democratic Party's platform said.

Sanders wants revisions in wording about U.S. relations with Israel and commitment to seeking peace between the U.S. ally and the Palestinians while preserving the commitment to Israel's security, those people said. They requested anonymity to discuss ideas for the platform that are still being developed. The platform is drafted by a Democratic National Committee panel and presented at the party convention in July.

The proposed new language on Israel is expected to seek what Sanders has elsewhere called a more even-handed U.S. approach to Israeli occupation of land Palestinians claim for a future state.

The current platform does not address the nearly five-decade occupation directly but endorses “a just and lasting Israeli-Palestinian accord, producing two states for two peoples.”

Sanders communications director Michael Briggs would not discuss the campaign's potential platforms plans.

"Senator Sanders has always and will always support Israel’s independence and right to live in peace and security. He also believes that lasting peace in the region will not occur without fair and respectful treatment of the Palestinian people," Briggs said. "We believe that most Democrats agree with that position and that a strong consensus will be achieved at the Democratic National Convention without a 'fight.'"

Speaking last month during a contentious debate with Clinton, Sanders said Israel’s 2014 military assault on the Gaza Strip was “disproportionate” to the threat posed by Hamas rockets launched from the Palestinian territory into Israel.

While declaring himself “100 percent pro-Israel,” Sanders said that if the region is ever to achieve peace, “we are going to have to treat the Palestinian people with respect and dignity.”

Behind his words is a long debate among U.S. and international policymakers about how to weigh Palestinian interests when dealing with Israel and whether resolute U.S. backing for Israel diminishes U.S. leverage to promote peace and fair treatment of the Palestinians.

It is a common view among many European nations and some American liberals that the United States is too forgiving of Israeli actions, including settlement building, that harm the Palestinians. It is also a common view at the United Nations and elsewhere that the United States will step in to defend nearly any action Israel takes, militarily or otherwise, and that Washington looks the other way at what Palestinians and their advocates call systematic human rights violations.

The Obama administration, both during and after Clinton's service as secretary of state, maintains that it criticizes Israel when warranted and works as an honest broker to promote peace. The four-week Gaza war in the summer of 2014 badly strained U.S.-Israeli relations, even as U.S. diplomats sought to defend Israel against criticism of its tactics, including airstrikes, in a densely populated area.

The White House used unusually tough language to condemn an Israeli strike on a United Nations school a few days before Israel accepted a cease-fire. The Obama administration nonetheless defended Israel against international criticism that Israeli action was improper "collective punishment" and  proclaimed that the U.S.-Israel relationship was strong and unchanged.

The most substantive discussion of Israel in the Democratic primary came during the debate between Clinton and Sanders in Brooklyn in April.

Clinton avoided a direct answer to whether Israel’s 2014 Gaza military barrage, which killed more than 2,100 Palestinians, was proportional to the threat. It is not clear how many of the dead were militants. The United Nations estimated that more than 70 percent were civilians, but Israel disputes that. Israel also says Hamas shares blame for civilian deaths by storing supplies and hiding militants in civilian homes and buildings.

“I don’t know how you run a country when you are under constant threat, terrorist attack, rockets coming at you,” Clinton said at the debate broadcast by CNN.  “You have a right to defend yourself. That does not mean that you don’t take appropriate precautions, and I understand there is always second-guessing,” she said. She endorsed continued U.S. efforts toward a “two-state solution,” meaning a separate Palestinian state alongside Israel.

The current U.S. policy position envisions a Palestinian state on most of the West Bank land now governed by the secular Palestinian Authority under Israeli occupation. The separate Gaza Strip, governed by the Islamist militant group Hamas, is supposed to be part of an eventual state but was mostly left aside during the most recent U.S.-brokered peace effort in 2013 and 2014.

The Israeli government and many pro-Israel advocates in the United States say calls for a more “even-handed” or “neutral” U.S. policy regarding the Israeli-Palestinian conflict are code for a view that discounts Israel’s security needs and overlooks Palestinian terrorism or incitement.

The U.S. government’s position on the major issues for a settlement -- borders, the status of Jerusalem and the rights of Palestinian refugees -- is that they should be settled through negotiation between Israelis and Palestinians as part of “final status” talks. The peace process is currently inactive.

Anat Berko, a member of the Israeli Knesset from Prime Minister Benjamin Netanyahu’s ruling Likud party and a Netanyahu ally, said Sanders’s goal of a more balanced U.S. policy toward Israel may sound sincere but is actually dangerous. It represents a failure to understand Israel’s unique position as a tiny democracy under threat of destruction, and allows those who hate Israel to hide behind the Palestinian cause, she said.

“To preach to Israel, it’s a great hypocrisy,” she said in an interview. “Please ask in my name Mr. Sanders why he’s not speaking about the denial by Iran of the Holocaust? The calling of Iran for the destruction of the state of Israel? Stoning in the streets of women? Of gays? To put the blame on Israel?” she said. “You need to identify your enemy, and if you don’t identify your enemy you’ve lost the battle.”

Elaine Kamarck, a member of the DNC rules committee who has been involved in drafting three previous party platforms, said the real work will come after the platform drafting committee, a 15-member body, is named. Draft language will probably be circulated after the California primary on June 7, she said.

She said she is not surprised that the Sanders camp may make things difficult for Clinton and the DNC.

“Part of the challenge of the challenger is to sort of find things that will be really difficult for the winner to accept. It sounds sort of funny but that's actually one of the goals,” she said.

“The inclination of the winner is to make no waves, make everybody happy and draw the party together. The problem with that is if you want to create a split or prolong a split or prove to your voters that this is not all for naught, you want to find issues that are as difficult as possible for the winner.”

A change in the wording on Israel could fit that bill, Kamarck said.

“We don’t know what form it will take, but obviously in general Sanders has been certainly more in favor of, you know, greater leverage for the Palestinians than Hillary Clinton has been. She’s been more of a traditional pro-Israel person,” she said.