Why do 15% of people think Vince Cable is sleazy?

On Tuesday Newsnight had an ICM poll showing that 57% of people thought that Gordon Brown was "tainted by sleaze". We've had a flurry of polls showing people think horrible things about Gordon Brown at a time when the government is getting a bad press, so it's hardly really newsworthy in itself.

The finding that actually caught my attention was that 15% of respondents thought that Vince Cable was was "tainted by sleaze". This seems quite flagrantly unfair to me - even if you think the Lib Dems are sleazy, poor old Vince has only been filling in for a couple of weeks, and seems to have done in it an entirely blameless fashion. Why do 15% of people think the poor man is tainted by sleaze?

My automatic assumption was that it was down to partisan responses. I am becoming somewhat dubious about the value of questions about party leaders attributes (and for that matter, questions about which party is best on particular subjects) because I think many people answer them in a purely partisan manner. Many people who support the Conservatives will probably give a negative response to any question about Gordon Brown, and vice-versa. They aren't really saying if they think Cameron is more competent than Brown or vice-versa, they are just saying they support the Conservatives and don't support Labour.

They only become interesting when you look at the party support breaks and see if it's all just partisan fluff (or when they are traced over time so you can look at trends). In this case the more worrying figure for Labour is probably that 53% of 2005 Labour voters think Brown is tainted by sleaze, rather than the negative opinion of the 74% of Tory supporters who probably aren't going to vote Labour whatever happens. The other questions are answered on broadly partisan lines - 79% of 2005 Tory voters think Cameron is cut out to be PM, 82% think he is competent; 67% of 2005 Labour voters think Brown is cut out to be PM, 67% think he is competent.

Going back to the original question though, this doesn't actually explain the Vince Cable figures. The people casting uncalled for aspersions on poor old Vince aren't gangs of partisan Tories and Labour voters - even 14% of 2005 Liberal Democrats voters think Vince is sleaze-tainted. The only explanation I can offer is that they are 'a plague on all your houses' voters who think all politicians are by definition sleazy!