Since Israel declared independence in 1948, the United States' two major political parties have expressed full support for America's closest Middle East ally virtually without fail.
That support has since the 1970s included the use of language, now boilerplate in both parties' platforms, that describes Jerusalem as Israel's capital - a status that, while claimed by the Israeli government, has never been internationally accepted.
Though no US president has ever attempted to recognise Jerusalem as the country's capital, and many have actively opposed the Congress's efforts to force such a move, both Republicans and Democrats officially profess recognition for reasons ranging from electoral politics to religious faith.
But that lockstep was embarrassingly broken on Wednesday night in Charlotte, North Carolina, where Democratic officials at the party's national convention discovered that the standard Jerusalem language had been omitted from their platform and had to push through a last-minute corrective, in the face of boos and perhaps majority opposition.
News of the unprecedented discord flashed around the world and drew immediate criticism from Republicans, who accused their opponents of wavering in their support of Israel.
"Under saner circumstances, this would be an almost perfunctory rephrasing of the US commitment to Israel in a way that does not fly in the face of longstanding US policy," wrote Daniel Seidemann at the Daily Beast's Open Zion blog. "Instead, it's perhaps predictably being used by opponents to mobilize political backlash of Biblical proportions - as some might believe befits an issue that in Israeli and American political circles (and among both Republicans and Democrats) has for years been dealt with not as sober, responsible policymaking, but as a heavy handed manipulation of domestic passion, real or imagined."
'Slap in the face'
How the Jerusalem reference was deleted from the Democratic platform for the first time since 1972 remains unclear. It also seemed far from certain that the decision to reinsert the reference received the necessary two-thirds approval from delegates in the hall. Convention chairman Antonio Villaraigosa, the mayor of Los Angeles, called for three successive voice votes before declaring the amendment was approved.
Debbie Wasserman Schultz, a member of Congress from Florida, told CNN the omission was "a technical oversight" and that there was no "discord" on the floor. But Jumana Judeh, a convention delegate and founder of Arab American Women for Obama, told Al Jazeera that she and others had intentionally lobbied to remove the reference from the platform.
"Once it became public knowledge, the Jewish lobby is a very powerful lobby here in the United States," she said, calling the decision to reinstate the plank a "slap in the face." Judeh said the lobbying group had filed a protest with the party, asserting that the amendment had not received enough votes.
Rami Khouri, a Middle East scholar at the American University of Beirut, told Al Jazeera that Americans "don't like to see their country manipulated by pro-Israeli or any other extremist, fanatic lobby group."
The omission of the Jerusalem plank was a "very significant" indication of changing attitudes, Khouri said, noting that President Barack Obama had at least tried, though failed, to challenge his Israeli counterpart, Binyamin Netanyahu, on the construction of illegal settlements in the West Bank.
"The lesson of this is not that the US believes the real capital of Israel is Jerusalem. It's an affirmation that Jerusalem is the capital of US policymaking," he said.
Democrats ' Jerusalem recognition
Republican and Democratic support for the state of Israel dates to the country's inception, but the obsession with Jerusalem is a more recent affair.
In 1948, the Democratic party platform applauded President Harry Truman for "[leading] the world in extending friendship and welcome to a people who have long sought and justly deserve freedom and independence." The Republicans went a step further, criticising Truman for "vacillation" on the issue and "[taking] pride in the fact that the Republican Party was the first to call for the establishment of a free and independent Jewish Commonwealth."
The first references to Jerusalem's status began after the 1967 war between Israel and its neighbours, which saw Israel push its borders on various fronts and take control of the city.
It was the Democrats who, in 1972, first made the call to "recognize and support the established status of Jerusalem as the capital of Israel" and move the US embassy from Tel Aviv to Jerusalem. Republicans made no mention of Jerusalem in their platform that year, when their candidate, Richard Nixon, defeated George McGovern in one of the largest landslide victories in US history.
Democrats have included similar language in every election year except 1988, when the Jerusalem reference disappeared in favour of a brief and nebulous promise to maintain the "special relationship" with Israel and "deliver the promise of peace and security" made at Camp David. (Democrat Michael Dukakis, labelled as an out-of-touch "Massachusetts liberal" by his opponents, fell to George Bush in another lopsided loss that year.)
Republicans made their first mention of Jerusalem in 1980, saying it should be an "undivided city" - a reference to Israel's full control - but it was not until 1996 that they caught up to the Democrats and included a platform plank declaring it Israel's capital. That decision was explicitly tied to the "Jerusalem Embassy Act of 1995" - passed by the first Republican-dominated Congress in four decades - which demanded the United States move its embassy, an act waived by successive presidents on national security grounds.