From what I remember of the Autumn 2009 pre-election briefing it sort of went like this.
We didn't expect to keep our 60 odd seats. We thought between 15 to 30 were vulnerable to the Tories. Cameron was going down well in some specific market segments who had voted for us in 2001 and 2005 (and had voted for Tonty in 1997 where they had been able to). It was hoped that Cleggers would help keep some of these (he did), there were some specific problems as well - where handovers didn't look to be going well and the seat liked Cameron (Bath, Harrogate, Hereford) and there was a problem in the West Country where UKIP had been eating into our NOTA vote. To balance this, it was hoped that about 20 seats might be taken from Labour, this was a bit optimistic. although there were issues in a couple of seats where Muslim votes gained 2005 were being brought back in the Labour fold - although in one case, highlighted, Rochdale - everyone was sort of "oh dear, how sad". There was some optimism that Clegg would "out fresh face" Cameron, which was sort of true. I could only imagine with the old Minger in charge, we might not have lost some older voters, older voters liked him, but we would have struggled with younger ones. The general outcome of this was, we would have done worse with Ming. Now what would have happened in Charlie had stayed off the sauce is another question, they would have been very different debates.