In discussing the Tories lack of support (pdf) among ethnic minorities, Rachel Sylvester in the Times (£) quotes a Tory strategist: "This is nothing to do with class or ideology. It's to do with history and brand."
What makes me suspect so is that successful brands are the product not of marketing campaigns but of history. Products such as Cadbury's chocolate, Bird's custard and Colman's mustard took off in the 19th century because they were initially better than rival products, and this built a trust that lasted.
And herein lies the Tories' problem. Ethnic minorities remember that, in the 60s, Tories hated them: "If you want a nigger for a neighbour, vote Labour." And just as people support Man United - probably Britain's biggest brand - because Charlton, Best and Law played for them, so they shun the Tories because of (folk) memories of the 60s.
In this sense, perhaps the Tories' anti-immigration policy backfires. Whilst it might appeal to the interests of (some? many?) ethnic minorites who compete in the labour market against new immigrants, it also reminds us of when the Tories really were the nasty party.
This poses the question: can the Tories rebrand themselves? I doubt it.
Branding needs an empirical basis; marketers can't fool the public for long. As Jonathan Salem Baskin says:
Branding is based on an outdated and invalid desire to manipulate and control consumers' unconscious. It looks good and feels good to the people who produce it, but it has little to no effect on consumer behaviour...It is the conceit that marketers can convince them of things that aren't substantiated by fact or the reality of experience. (Branding only Works on Cattle p14, 17)
Because of this, many efforts at rebranding have failed: think of the Post Office calling itself Consgnia or HMV's efforts to sell electronic tat. Where rebranding has worked, it's been through luck (eg Burberry's appeal to urban youth in the 90s), or through good new products (such as Apple's shift from computers to iPods and phones, or Sony's entry into games consoles markets) or because the company has a longstanding appeal that only needs brushing up (eg Marks & Spencers passim). It's not clear that the Tories have any of these advantages.
Of course, the Tories' actual policy platform isn't hostile to ethnic minorites any more - it's difficult to see a policy reason why Indians should split 61-24 in favour of Labour over the Tories - but this is not sufficient. If a car is going downhill, it won't change direction if you only put it into a neutral gear.
Perhaps, therefore, the Tories are victims of path-dependency. Maybe marketing men cannot fight against history.