There is, of course, something of an inevitable divide between parties at Westminster and parties campaigning locally. For the Lib Dems, this is exacerbated by the emergence of a new cadre of special advisers and party staff who might not even have been members before 2010.
I don't want to give away much about this conversation, because it wouldn't be fair. But what took my breath away was the gulf between parliamentarians in government (deeply pragmatic) and parliamentarians who still regard themselves as grassroots campaigners.
Most Lib Dems are both - they have to be - so this tends to be a psychological divide. It is a divide in the soul. And it set me thinking about what happens to political parties once they find themselves in government.
I have no evidence for these assertions, except my own eyes. But I have a feeling that the experience, and the pressure and frustrations, affect different ideologies differently.
For Conservatives, a few years in the mangle of government, and they come out deeply cross, perhaps even arrogant. Their fundamental sense of their own entitlement to power becomes more evident. They become beset at a deep level by rage that they are being questioned at all.
Often these transformations seem to me not only to bring out the shadow side but to be experienced as major irritation. For the Conservatives, the irritation is that they are being prevented - by the leadership, the coalition, the Eurocrats, the liberal establishment - from ruling as they see fit.
For Labour, the shadow side is different. They become micro-controllers, enraged at the failure of institutions and individuals on the ground to fall into line in the way they expected. They they become arch-centralisers.
Incidentally, this means that - while I'm delighted at Ed Miliband's recent campaign about setting the cities free - I remain slightly sceptical about the ability of a Labour government to see this through.
Which brings us to the Lib Dems. Their rage in government is directed at impractical idealists, those whose failure to be pragmatic enough - to fully understand the barriers to change - are preventing them making progress.
They become arch-pragmatists, prepared to accept almost any compromise if it avoids the humiliations of powerlessness that seem inevitably to come with power. Interested only in the specific path to making things happen.
That was the difficulty when Lib Dems ran so many local councils. The councillors in power tended to forget their ideological roots, and began to believe in good, pragmatic government, and consequently lost their compass and stopped innovating.
A little pragmatism isn't a bad thing. I've had a homeopathic dose of it on the very fringes of government, and feel it has done me good. I was, after all, one of those impractical idealists, deeply committed to vague change, the details of which eluded me.
But then, maybe that's what they all feel.
What do we do about it? I don't know, but a little self-knowledge can work wonders.
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