He was too right-wing for Fox TV, or at least for the 400 advertisers who told the network earlier this year they no longer wanted their commercials on his now-cancelled talk show. He provoked international outrage by saying the Norwegian youth camp where 68 people were massacred in July bore "disturbing similarities" to the Hitler Youth. He has horrified the staunchly pro-Israel and anti-racist Anti-Defamation League with his "bigoted ignorance" in comparing reform Judaism to "radicalised Islam".

Yet tonight Glenn Beck, the American super-shock-jock with views which Tea Party Republicans love, but which many Israeli – as well as US – liberals regard as beyond toxic, will be the undisputed star of a "Restoring Courage" rally in Jerusalem. The event is designed to underline his fierce identification with the Israeli cause, or at least, the Israeli cause as he defines it – a cause for which he says he is willing to die.

The organisers speak in slightly less radical terms. They say the rally will call for "unity among all faiths" as well as issuing a call to "all citizens of the world to stand with and declare their support for Israel". Beck is pushing that view to its sentimental limit. In a frequently tearful speech at a warm-up rally in Caesarea on Sunday night, Beck proclaimed: "Let the Jewish people know, no matter what our governments may say... we stand with you."

Beck insisted in a Jerusalem Post interview this week that he is "not here for politics". Many are unconvinced. Joanna Brooks, a US expert on Mormonism, the faith Beck was converted to in 1999, argued in the online magazine Religion Dispatches that Beck sees tonight's rally – at which he will appear with the famously right-wing Hollywood actor Jon Voight – as part of "a latter-day crusade to save the Holy Land from the Palestinians". A flavour of the views he expressed at his packed "Restoring Honour" rally in Washington a year ago shows how far Beck identifies with the pro-settler far-right in Israeli politics.

"There are forces in this land, and forces all over the globe, that are trying to destroy us," he told his ecstatic audience then. "They are going to attack the centre of our faith, our common faith, and that is Jerusalem. And it won't be with bullets and bombs. It will be with a two-state solution that cuts off Jerusalem, the Old City, from the rest of the world."

Jerusalem's secular mayor, Nir Barkat, will attend tonight. His spokesman said yesterday he would "give introductory remarks as he does at almost all events that bring over 1,000 visitors from abroad". A clutch of Knesset members and right-wing religious leaders are also expected.

But many, if not most, of the 1,600-strong audience will be from abroad – mainly American supporters who have flown in for an event which the organisers say has pledges of support from Democrat Senator Joe Lieberman, Mort Zuckerman, the Canadian-born billionaire publisher of the New York Daily News, and Republican presidential hopeful Rick Perry. They will include representatives of Christian Zionism, whose passionate support for Israel is complicated by a belief among many of its adherents that Jews will have to convert to Christianity before the second coming of the Messiah.

Some Arab Knesset members have warned that the event could lead to violence because of its proximity to the Old City. It will be held near an East Jerusalem site of archaeological excavation close to the Western Wall of the site sacred to Jews as the Temple Mount and to Arabs as Haram al Sharif. But there are also Israeli Jews who are seriously perturbed by the gathering, which Beck is organising, he says, without a commercial profit.

Peace Now is promising a "large protest". It wrote yesterday to popular Israeli singer Dudu Fisher urging him to cancel his planned attendance. "There is no place for extreme political rallies at the holy site," it said. "There is no place for collaboration with a person like Glenn Beck. We call upon you... not to contribute your rare voice to this terrible event."

Beck also hardly endeared himself to the hundreds of thousands of Israelis who have been protesting against government economic and social policies; he compared them last week to Soviet-style communists and suggested they may have been joined by "Islamist" activists.

Beck's visit coincides with – though is not linked to – a visit by 26 Republican members of Congress. This is part of a much larger push by pro-Israel lobbyists in the US to bring 81 American legislators of both parties, including half the freshmen Republican Congress members, to Israel and the West Bank. Although such trips happen every year, this one, organised by an educational charity affiliated to the American Israel Public Affairs Committee, has an added edge because of Palestinian plans to seek UN recognition of a Palestinian state based on 1967 borders. The move is strongly opposed by Israel and will be vetoed by the US if it goes ahead. Congressional leaders have already threatened to withhold funding of the Palestinian Authority if it pushes ahead with the plan.

The groups have been scheduled to meet the Palestinian President, Mahmoud Abbas, as well Israeli leaders. But their visit is likely to be overshadowed by Beck, who opposes not just the approach to the UN, but the idea of a Palestinian state. Prominent Haaretz blogger Bradley Burston said the irony was that the two-state solution Beck demonises "is probably farther from reality now than it has been at any time in the last 18 years", adding: "But what is irony to a man... for whom most Israelis are not hardline enough and therefore not Israeli enough... a man who knows better than the Jews what Auschwitz means, who Nazis are, what Israel needs, and how Jews figure in the greater plan of God and His Apostle Glenn?"