If we take a look at conjugate base of benzoic acid it is as given below:
Now my question is:
Is delocalisation of non bonding electrons(in the carboxylate part) into the benzene ring possible?
Critical Comment:I think that it won't be possible because we would end up having negative charge on both the oxygen which should make it less stable.
Reference supporting my claim:
Although the reason I gave may or may not be the actual,i don't know, but the reference also claims the same thing i.e delocalisation of non bonding electrons doesn't occur.
scroll down and check this: Factors controlling acidity and under that check 'substituent effects for some aromatic carboxylic acids'