Could the next nominee of President Trump to fall to the Democrats be his prospective ambassador to Israel, David Friedman? His nomination is already being opposed by critics of Israel, including a left-wing Jewish group. But on the eve of his confirmation hearing today in the Senate, five former American envoys to the Jewish state sent a letter to the Foreign Relations Committee urging a rejection of the nominee on the grounds that his “extreme positions” make him “unqualified to the position.”

What is so shocking about this letter is that it runs so contrary to the views of the new president. Even while the letter was being circulated, Mr. Trump was meeting with the Prime Minister of Israel and — as CNN put it — “rejecting” the “long-established U.S. framework for Middle East peacemaking.” The acceptability of an agreement, in Mr. Trump’s view, is not defined by the number of states it creates. “I’m looking at two-state and one-state,” the president said, “and I like the one that both parties like.”

Clearly such thinking is upsetting to the ex-ambassadors, though their letter appears to have been drafted before Mr. Trump’s meeting with Prime Minister Netanyahu. The former envoys — Thos. Pickering, Wm. Harrop, Edward Walker, Dan’l Kurtzer, and Jas. Cunningham — are all distinguished career foreign services officers. They are upset by reports that Mr. Friedman views a two-state solution as “illusory” and supports Jewish settlement of Judea and Samaria.

The ambassadors allege, among other things, that Mr. Friedman has “accused President Obama and the entire State Department of anti-Semitism.” We don’t share that view, but the State Department has long been stained by anti-Semitism, going back to the days of the arch-anti-Zionist Loy Henderson. It’s hard to imagine Mr. Friedman believes all members of the department are anti-Semitic, but it’s also hard to imagine the distinguished ambassadors are unaware of the history of this problem at Foggy Bottom.

In any event, the ambassadors’ ostensible beef is with Mr. Friedman’s — and the president’s — doubts about the two-state solution. The career diplomats reckon that this has been a “bi-partisan goal of U.S. foreign policy for decades.” Why, though, if the policy has been in place for decades and failed to achieve a peaceful resolution is it so all-fired improper that a new president would be inclined to send to the Middle East an envoy prepared to explore something new?

Particularly when voters asked for a change. We have just come through eight years of the most acrimonious relations between Jerusalem and Washington since the establishment of the Jewish state. A senior “official” of the last administration was referring to the Israeli premier as chickenshit. One could instantly see in the first encounter between Messrs. Trump and Netanyahu yesterday that there is almost a sense of relief, genuine warmth. It may not last, but what a contrast with such visits in the past eight years.

Hence the importance of the fight over Mr. Friedman and the hearing today. Haaretz reckons the vote in the Foreign Relations Committee is an open question. It lists ten of the 11 Republicans on the committee as likely votes to confirm. It lists four Democrats — including, naturally, Secretary Clinton’s vice presidential nominee, Senator Kaine — as likely to oppose Mr. Friedman. It includes Senator Rand Paul and six Democrats as “unclear.” Several of the “unclears,” such as Senator Menendez, are terrific on Israel.

We’ve already expressed the view that it is a mistake for Mr. Trump to put a priority in making peace between Israel and the Palestinian Arabs. He should have learned from the humiliation of Mr. Obama (among others). But it would also be a mistake, having appointed an ambassador with a deep understanding of the situation, to let him fall to a protest from a foreign policy establishment that wants it, rather than the voters, to set policy. If Mr. Trump loses this fight, he will only undercut his prospects elsewhere.