The Mail is an oddity I am reminded. These days as far as influence goes it's more of a closed shop than commentators realize (unless you read it, you deride it) but because commentators don't realize this it has a big impact on how broadcasters cover things.

Yes, the issue isn't the partisan press per se, because it's always been a feature of the landscape, it's that the only people outside its core readership who read and take it seriously are journalists.