At least he didn't burst into tears. But Nick Clegg looked as though his patience was wearing very thin, that he was surrounded by fools, that nobody understood what he was going through, that he couldn't be expected to be any less irritable with so much caffeine and so little sleep.
"Insofar as you listen to anything I say," he told one with that passive aggressive tone we use on our adolescent sons. And later, laughing at delegates for being nice to him: "Heavens, what docility, it's almost North Korean!" And later still, derisively: "I'm being clapped for a sentence I haven't even finished!"
The chair fed him soothing questions selected from the audience's submissions earlier in the day. The conference were keen to support their leader, to show him their affectionate loyalty – but he rarely looked other than exasperated. He was so far from taking any criticism, he was actively looking for a fight.
One young man asked if it was embarrassing being in coalition with a prime minister who took on interns from his friends' families. Clegg wound himself up to say, "It's not for me – or even for you to make that judgement." Then went on at full steam to say how no one should EVER be ashamed of doing EVERYthing they can for their children.
He rebuffed a woman who asked him to tell of the influence he had over David Cameron and denounced his critics as "shrill" and "tribal".
His friends will call it a blistering performance; it looked to me like a man braced for impact. "We've got to stop beating ourselves [ie, me] up," he cried.
Earlier in the day we had Vince in a very different posture. His assessment of the situation may be proven comically optimistic as events unfold but he had a good crack at constructive pessimism.
"The public is tired of being lied to and promised what can't be delivered," he said sombrely. And then told us how our savings would be channelled into productive investments, how responsible capitalism would be delivered, that we could even escape the famine and feast of bank lending and that he'd make sure the recovery was built on fairness.
And maybe he will – as long as the international monetary system doesn't collapse first. We can only hope that that happens, when it does, fairly.