WASHINGTON — President Trump plans to throw his full weight behind Benjamin Netanyahu’s campaign to save his job as prime minister of Israel. But to do that, analysts and former diplomats said, the president will have to sacrifice any last hopes of proposing a peace plan that is acceptable to both Israelis and Palestinians.

Mr. Trump’s son-in-law and senior adviser, Jared Kushner, met Mr. Netanyahu in Jerusalem to discuss the status of the plan on Thursday, hours after the prime minister failed to form a governing coalition. Mr. Kushner emerged with a longer timetable and a narrower diplomatic mission, these people said.

Rather than make concessions to the Palestinians, Mr. Kushner will be under pressure to tilt the plan ever further in Israel’s favor. Far from being a bold effort to break decades of enmity between the two sides, it could end up becoming a vehicle to resurrect Mr. Netanyahu’s political fortunes and to protect Mr. Trump’s.

The plan, which Mr. Kushner has drafted under a veil of secrecy for more than two years, was already looking like a doomed effort. Though its details remain unknown, Mr. Kushner has suggested it will not call for the creation of a Palestinian state, jettisoning decades of American policy toward the conflict. The Palestinians have vowed to reject it out of hand, branding it a blueprint for Israeli domination.