There is nothing liberals like quite so much as a sex scandal involving a conservative. If the conservative is also a Christian, a unionist, a DUP unionist at that, with a reputation for mouthing off in genuinely offensive ways about minority groups, then so much the better.
Iris Robinson is obviously a deeply silly woman. But she knows that and doesn't need me sticking another blade between her ribs to join the forest of blades that is already there. She is also very unwell, which is what makes some of the attacks on her so unsavoury, not to say merciless.
Robinson is accused of preaching a harsh, Old Testament brand of morality, in keeping with her particular brand of religion.
Therefore, say her opponents, she deserves all the criticism she's getting.
But even allowing for the caricature that Old Testament morality is all about judgment and condemnation, what could possibly be more judgmental and condemnatory, more 'Old Testament', than the avalanche of criticism currently pouring down on Robinson's head?
The abuse she is receiving on the airwaves, in the blogosphere, from some columnists, is reminiscent of the vitriol poured down on Sarah Palin's head when she first appeared on the scene.
The similarities between the two women are striking. Both are Evangelical Protestants. Both are conservatives. They are both pro-life and pro-marriage. Both seem to like the limelight. Both women are also fairly glamorous in that slightly vulgar, flashy sort of way that brings out the snob in lots of middle class people.
But Robinson has played into the hands of her enemies in a way Palin never did (not that they needed any excuse to savage her), because Robinson had an affair with a man 40 years her junior.
Nothing separates conservatives from liberals quite so much as sexual morality. Conservatives believe in commitment and fidelity, in sticking with one person for life.
Liberals believe in freedom. If you want to commit to someone for life, that's fine, they say. But if you don't, if you want to play around, then that's fine too so long as no-one gets hurt.
But the big rule, the number-one rule of liberals is that you should never, ever preach any kind of sexual standard apart from that broadest and most permissive of all standards, 'anything goes between consenting adults'.
If you preach any higher standard than this, they will resent you. But if you preach a higher standard, and it turns out you have not lived up to it yourself, they will rend you limb from limb.
Thus, Robinson is more reprehensible in their eyes than Bill Clinton, with his many affairs. Or Roman Polanski, who pleaded guilty to the statutory rape of a 13-year-old. Or Oscar Wilde, who had a well-documented fondness for 'rent boys', which is to say, boy prostitutes.
So although Robinson's behaviour, objectively speaking, is no worse than Clinton's, and is much less appalling than that of either Polanski or Wilde (who was married, let us remember), nonetheless she is worse than all three in liberal eyes because she preached a standard of sexual behaviour and didn't live up to it.
In fact, the liberal hatred of hypocrisy is extremely dangerous because there are only two ways to avoid hypocrisy. The first is to live perfectly, while the second is to preach nothing.
But none of us is perfect, and therefore the only sure way to avoid the charge of hypocrisy is option two, to preach nothing and abandon practically all standards.
In the sexual sphere that is exactly what has happened and we are much worse off for it. The sum-total of human misery has undoubtedly been increased by the modern sexual revolution, with its attendant high divorce rate, the collapse of marriage in certain areas in favour of cohabitation, the abandonment of thousands of young children by their fathers, and all those countless individuals left broken-hearted by people who never committed to them, or who broke their commitments.
This is what happens when you stop emphasising fidelity, when you stop emphasising commitment, when you stop promoting marriage, when you stop preaching standards, all in the name of freedom. You might reduce the amount of hypocrisy but it will come at a huge cost.
Robinson did wrong. But her greatest wrong wasn't her hypocrisy, it was her infidelity, which has devastated her family, as it always does when discovered.
What we need to do now is to leave her alone while she tries to pick up the pieces of her shattered life and put them back together again.
The best way for her to do that isn't to abandon her standards, but to live them better.