I'm a lot more widely read than the Mail - which I do not actually even read! But I must admit that I have reluctantly given up on the present-day conventional wisdom regarding crime, so maybe that makes me equivalent to a Daily Mail reader.
The establishment, the broadcasters, the government, the judiciary, the upper ranks of the police force, the Guardian columnists: they've all got it dead wrong, and demonstrably so, but they insist on continuing to push bad policies because politics makes it impossible to do otherwise. Who dares break rank and point out the emperor's nakedness, thus effectively siding with the Daily Mail? It would be professional death.
I don't expect to convince you to switch sides, even though you are surely not under the same pressure to conform, but let me bring up two little things to challenge you.
Firstly, is the "us and them" mentality really unhelpful? I say not. In fact, it is a principle of civilisation - which can only exist by making a distinction against the uncivilised. "Us and them" is essential. We are civilised, they are not. We respect other people and their property, they do not. We don't break laws, they do.
Perhaps you know of the expression, "the thin blue line", which refers to the police force? The line is the division between "us and them" - the purpose of the police is to enforce it by defending "us" against "them". If there is no such line, because we are "them" and they are "us", then what is the purpose of the police? And indeed, the law, if the lawbreaker and the law-abiding are one and the same?
Secondly, you say that "Punishment...does little to reduce crime levels. In fact all it appears to do is increase them." A common enough meme these days - Ken Clarke MP shares it with you - but it doesn't explain the low crime rates in places with both robust law enforcement and an effective penal system. Examples might include present-day Singapore and 19th century Britain.
You have already countered that America has tough law enforcement and plenty of crime - but America's law enforcement is geographically incomplete, as evidenced by the prevalence of gangsters and systematic violence in some areas. If law enforcement is really so tough, how come any places are run by criminals? I'd also question whether America's penal system is really any good, given that federal prisoners now expect to be gang raped in prison. Clearly, an effective penal regime would not permit any gangs (or rapes) in prison.