[gerard.casey]

The appeal to authority is an informal fallacy, which is to say, it’s not always wrong. It’s wrong when you appeal to someone who is not an authority in respect of the subject matter under discussion: “Now’s a good time to invest in commodities.” ‘Why?’ ‘My dentist told me so.’

Rhetorically, it makes perfect sense to associate your claims with people whom you can reasonably expect your intended audience to respect. Assuming the association is legitimate, it doesn’t, of course, just by itself establish the truth of your claim but it should ensure it a more respectful and considered hearing for it.