It had been a very good night out, said Sarah Smith on the phone from the United States. A very good women-behaving-warmly kind of thing. Until they got on to politics. Then, said Channel 4's Washington correspondent, she could hardly believe what she was hearing.

Her companions were professional women in their forties and fifties; all lifelong Democrats, all veterans of the recent campaign to make Hillary Clinton the presidential candidate. Now, they told Sarah, not one of them planned to vote for Barack Obama. Neither were they going to sit on their hands. They'd decided to vent their wrath at their woman losing the nomination by voting Republican and plighting their troth to John McCain.

Their rationale was that if all the women disappointed at losing a golden opportunity to elect the first female President of the US gave their party a bloody nose in November, then that party would learn the hard way that you don't mess with the female vote.

It would maybe cause short-term pain, but flexing their electoral muscles would ultimately benefit their granddaughters. This is surely the politics of the perverse, and the politics of the supremely illogical. Nevertheless, canvassing the opinion of a number of Americans in Edinburgh for the festival, you find a depressing lack of surprise. Several suggested that Hillary was not so covertly encouraging this lack of enthusiasm for her party's choice in order to bolster her own chances of a second run at the top job four years hence if McCain beats the odds and Obama.

Let's hope that's not so. Let's hope that the woman who attracted that fierce brand of female loyalty in the first place is not so subsumed by personal ambition she has calculated that four more years of Republicanism will be good for her cause, so to hell with her country.

In fact, let's just suppose it's not so, but try to unpick the craziness that would have her erstwhile campaign workers turn their back on a lifetime commitment to the Democrats simply because their party endorsed the "wrong candidate".

According to Sarah Smith, the rage of these women was based on the fact that they were just months away from an able and talented woman getting into the White House - this time through the front door - when an upstart, relative rookie popped up from nowhere and dealt her a mortal blow. It's an interesting take on democracy that it's only valid if the electorate supports the candidate you want. What we might call the Mugabe school.

These women clearly feel betrayed, but in truth they're in serious danger of betraying their party, their country and the children and grandchildren about whom they profess to care so much. Obama may be rowing back from some of his more liberal stances, but he has refused to be nailed by the religious right over abortion and contraception; he has a solid record on equal pay and opportunities.

Compare and contrast the supposedly independent-minded John McCain, who was swift to tell a congregation this past week that life began at conception, and who, when asked about supreme court appointments, name-checked the only surviving liberal judges as the ones he would not personally have appointed. The McCain once portrayed as a maverick not afraid to challenge a sitting President has emerged as an all too traditional wolf in wolf's clothing, now shamelessly pandering to whatever right-wing constituency comes along in order to tie up the votes and the cash which might help him close Obama's slender lead in the opinion polls.

That stubbornly slim margin is all too vulnerable to the still vibrant seam of racism in American politics without supposedly intelligent female voters switching their allegiance from the candidate and the party most likely to protect their rights, many of which have been under sustained assault by the forces of Republican darkness.

It's like the Fawcett Society deciding to vote for David Cameron because Gordon Brown hasn't been sufficiently respectful of Harriet Harman.

It may be, as her supporters insist, that Hillary Clinton is a supremely able and experienced woman who would have brought a formidable intellect to the challenges of first female President. It may be, as her detractors darkly hint, that she is a manipulative and scheming politician wholly focused on shinning up the greasy pole regardless of who and what gets ditched in the process.

Either way, what she isn't is the first choice of a majority of those who cast their votes in the primaries and caucuses of the past half-dozen months.

Liberal Democrats who voted in other directions need to dry their tears, park their pique and get behind the only person now able to prevent four more years of what the British used to call "Conservative misrule".