Even as George W Bush repeated, yet again, his determination to “stay the course” in Iraq, the war looked like claiming another high profile casualty.

Senator John McCain, once frontrunner for the Republican presidential nomination, has lost two key advisers, and the media are speculating over how long he will remain in the race. McCain is now placed fourth in the polls, behind Rudy Giuliani, Mitt Romney and the yet-to-announce Fred Thompson.

The senator’s woes follow his announcement last week that he had raised only (!) US$11.2 million in the June quarter and had only US$2 million cash on hand, news which led to a severe downsizing of his staff.

Campaigning in America is an expensive business. Even so, no candidate actually needs that much money at this stage. The real point of the fundraising figures is that, in the absence of any real electoral tests, they are used as a proxy for support. If people won’t donate to McCain, it’s being assumed they won’t vote for him either.

So how important is the war in this? Certainly McCain has other negatives, including his age. But he has been the most strident of the candidates in support of the president’s Iraq policy, whether through conviction or as a deliberate effort to counter his anti-Bush past. He was an early promoter of the “surge”, and after a visit to Iraq this week he insisted that things were “moving in the right direction”.

Being pro-war isn’t exactly a distinguishing characteristic among Republican candidates. But McCain’s high-profile identification with the current policy makes him the most obvious target for public anger, particularly since most of his support, in light of his previous record, would have been expected to come from relatively moderate voters.

The interesting question is whether any of the other Republicans will take the hint and try to take advantage of anti-war sentiment. So far Ron Paul, maverick libertarian from Texas, is the only one to call for a troop withdrawal. But the growing drift of Republicans in Congress away from Bush’s policy shows that support for the war is no longer de rigueur in the GOP.

Despite the mythology, it was not the Democrats that brought down Richard Nixon over Watergate, it was his large-scale desertion by Republicans. Similarly, only the Republicans can end the Iraq disaster. Some reconsideration by Giuliani, Romney or Thompson would be a good place to start.