In his speech to the American Israel Public Affairs Committee in Washington, the Republican nominee-in-waiting expressed disgust for Senator Obama's declared willingness to meet President Mahmoud Ahmadinejad of Iran without preconditions.
"It's hard to see what such a summit would gain, except an earful of anti-Semitic rants and a worldwide audience for a man who denies one Holocaust and talks about starting another," Senator McCain said.
He said Senator Obama's plan for a withdrawal of US troops from Iraq would "result in a catastrophe" and a potential terrorist sanctuary in the heart of the Middle East. This "would profoundly affect the security of the United States, Israel and our other friends".
The sensitivity of the Obama campaign to such charges was reflected in the 3835-word rebuttal it issued even before Senator McCain had finished speaking.
It pointed out that Senator Obama had sponsored a sanctions bill against Iran and emphasised that he would consult military commanders on the withdrawal from Iraq.
Although the Jewish vote in the US is relatively small, Democrats have relied on it in key swing states such as Florida and Pennsylvania. Christian evangelicals - who represent a huge slice of the electorate - are also fervently pro-Israel.
Yesterday, Senator Obama's aides circulated recent polling that showed he led Senator McCain among Jewish voters by a margin of 61 to 32 per cent.
Senator Obama has been dogged by claims his position on holding talks with Iran reflects a broader view - expressed openly by some of his past associates - that Israel is responsible for much of the Middle East's problems.
The campaign recently and swiftly severed links with Robert Malley, one of its informal advisers, after it was disclosed he had been in contact with the Palestinian organisation Hamas, listed by the US State Department as a terrorist group.
It also distanced Senator Obama from former national security adviser Zbigniew Brzezinski, who has been sharply critical ofIsrael and similarly has called for the US to have direct contact with Hamas. Last year, Senator Obama praised Mr Brzezinski as someone "I've learnt an immense amount from".
Yesterday, an Obama spokesman described Mr Brzezinski as a "supporter" who was not and had never been an adviser.
The campaign office refused to comment on allegations in right-wing blogs that Senator Obama has employed a number of Nation of Islam members.
Under federal civil-rights law, it was illegal to ask staff about their religion, the spokesman said.
Jewish groups such as the Anti-Defamation League say the Nation of Islam, founded by Louis Farrakhan, is less of a religion than a vehicle for anti-Semitic hatred. Senator Obama has been at pains to emphasise he has "always denounced the abhorrent anti-Semitic views of Louis Farrakhan".
Lee Rosenberg, a member of AIPAC's national board, said: "I've known Barack Obama for eight years. Throughout that experience, including travels together to Israel, he has always been a friend of Israel."
He suggested suspicion of Senator Obama among some Jewish groups was because "people don't know him properly yet".
In such a climate it is significant that Senator Obama's foreign policy adviser, Tony Lake, has recently chosen to disclose his conversion to Judaism.
In an interview last month, Senator Obama made yet another effort to explain why Israel would not be hurt by any negotiations he had with its traditional enemies.
"I welcome the Muslim world's accurate perception that I am interested in opening up dialogue and moving away from the unilateral policies of George Bush," he said.
"But nobody should mistake that for a softer stance when it comes to terrorism or protecting Israel's security."
The Republican National Committee is circulating damaging quotes from Senator Obama.
These include comments such as "nobody is suffering more than the Palestinian people" and an apparent failure to remember that Israel is among the US's closest allies, as well as a suggestion that the violence of Hezbollah and Hamas "weakens their legitimate claims".
The Times
