Why such a warm reception for Benjamin Netanyahu at US Congress?

The moment many US lawmakers were waiting for came toward the end of Israeli Prime Minister Benjamin Netanyahu's speech Tuesday to a joint session of Congress. "Israel will not return to the indefensible boundaries of 1967," he said, to a vigorous burst of cheers and applause.

With that, Mr. Netanyahu may have demonstrated that the American Congress stands with Israel, and not with President Obama, on the matter of a starting point for resuming peace talks with the Palestinians – if and when such negotiations ever do resume.

That, perhaps, does not come as a huge surprise, given the shared Judeo-Christian tradition and shared democratic values. But there's also the pro-Israel lobby, long one of the most effective on Capitol Hill. Since 1990, pro-Israel groups have contributed more than $97 million to congressional candidates – 67 percent to Democrats and 33 percent to Republicans, according to the Center for Responsive Politics in Washington. Some 38 lobbyists are registered on pro-Israel campaigns, spending more than $8.6 million to lobby Congress and the White House since Mr. Obama took office.

The pro-Israel lobby is also sustained by a robust grass-roots operation, on display Tuesday as thousands of people attending the annual meeting of the American Israel Public Affairs Committee (AIPAC) jammed congressional corridors to lobby lawmakers on controversies of the day, including cutting aid to the Palestinians, blocking a United Nations vote on the creation of a Palestinian state, and defusing talk of a return to Israel's 1967 borders.

Democrats and the vice president, who also attended the speech by "Bibi," sought to play down a rift between Obama and the Israeli prime minister. Reports of a rupture in relations proliferated after Obama said during a major address last Thursday that Israel's pre-1967 borders should be the basis for establishing territorial boundaries of Israel and a new Palestinian state, with mutually agreed land swaps to account for Israeli population centers in land held after the Six-Day War.

Republican presidential candidates, meanwhile, claimed that rifts had emerged between Israel and the Obama administration – and within Democratic ranks over the president’s remarks. And Rep. David Dreier (R) of California noted to fellow House leaders that Vice President Biden was among those applauding Netanyahu's line in the sand on the 1967 boundaries. (As a US senator, Mr. Biden was among the strongest supporters of Israel in Congress.) Did his applause signal that he is distancing himself from the president?

House Democratic whip Steny Hoyer (D) of Maryland chalked up Biden's response to a clarification. “More was made of the 1967 reference than was intended,” he said, referring to the tempest over the president’s remarks. The press should have paid more attention to Obama’s calls to negotiate new borders, which included the likelihood of land swaps.

“The president clarified that when he spoke [on Sunday] to AIPAC, and I think the vice president recognized that,” Mr. Hoyer added.

Other senators were not convinced. Sens. Orrin Hatch (R) of Utah and Joseph Lieberman (I) of Connecticut plan to introduce this week a draft resolution in support of Israel that calls it “contrary to US policy and national security” for Israel to return to the borders of 1967 or 1949.

“The resolution says that we in Congress agree that we’re not taking this back to the borders of 1967 or 1949,” said Senator Hatch, who wants to put all lawmakers on record on this issue. “That’s just the way it is.”

Biden, commenting as he exited the House chamber, said he did clap at that point in the speech – and meant it. “There’s no difference between what Bibi said and what the president said [on this issue],” he said. “The president believes very strongly that there has to be significant negotiations and swaps. No one suggested that the territory around Tel Aviv doesn’t have to remain in Israel. Bibi said this has to be negotiated between Israel and Palestine.”

Presidents who cross the pro-Israel lobby typically do so at their peril. In 1991, Congress pushed back against a bid by President George H.W. Bush to withhold $10 billion in loan guarantees to pressure Israel to curb new settlements in “occupied territories." President George W. Bush also had to roll back threats to reduce US loan guarantees to Israel over construction of a wall on contested soil.

In Netanyahu's nearly hour-long speech, interrupted frequently by cheers and ovations, the prime minister invoked a deep friendship with the United States and the new struggle for freedom “from the Khyber Pass to the Straits of Gibraltar.” He warned lawmakers that Iran’s nuclear aspirations threatened the US capital as well as Israel, and he rejected calls to impose a Palestinian state through the United Nations. He called on Palestinian President Mahmoud Abbas to tear up his pact with Hamas, stand before his people, and say, “I will accept a Jewish state.”

“Those six words will change history,” Netanyahu said. “They’ll make it clear to the Palestinians that this conflict must come to an end – that they’re not building a Palestinian state to continue the conflict with Israel but to end it.”

In a nod to Obama, Netanyahu said both leaders agree that the 1967 borders will not be the end of any negotiations with the Palestinians.

“In any real peace agreement, in any peace agreement that ends the conflict, some settlements will end up beyond Israel’s borders,” Netanyahu said. “Now the precise delineation of those borders must be negotiated. We’ll be generous about the size of the future Palestinian state. But as President Obama said, the border will be different than the one that existed on June 4, 1967.”