In Ashes to Ashes, its predecessor Life on Mars, and the newly established George Gently, there is a very powerful negative presentation of the past relative to now. The casual and institutionalised racism, misogyny, homophobia and violence of the police forces of 1982 in Ashes to Ashes & 1973 in Life on Mars are set before us to show clearly pointedly and deliberately that the reforms and changes that the police force & (as they are the synecdoche of society by implication [or should that be 'by connotation']) we have gone through were for the better. That our society now is better because although it is still bigoted and violent it is not as bigoted and violent as it was in earlier decades and that this was achieved through a worthwhile struggle is something to be cheered and there is a certain chorus of approval for our world (for now) in Ashes to Ashes and Life on Mars [see here for a fuller analysis].
There is a similar but more legally focused version of this trumpeting of NOW in George Gently. The law is especially criticised in Gently; the death penalty [effectively ended in 1965], the criminalisation of suicide [ended in 1961], the criminalisation of abortion [until 1967] and the legal frameworks of parentage and child protection have all been criticised in this current series and all through the 'ideology of now'.
The problem of this use of the 'ideology of now' to criticise the past and reflect on the strongly negative aspects of the police and the criminal justice system is how closely it is patterned after the trope of 'inoculation' that we find in one of Roland Barthes' more intriguing mythologies; Operation Margarine.
To instil in the Established Order the complacent portrayal of its drawbacks has nowadays become a paradoxical but incontrovertible means of exalting it. Here is the pattern of this new-style demonstration: take the established value which you want to restore or develop, and first lavishly display its pettiness, the injustices it produces, the vexations to which it gives rise, and plunge in into its natural imperfection; then, at the last moment, save it in spite of itself, or rather by the heavy curse of its blemishes.Barthes is very clear in this short mythology that 'a little confessed evil' is a powerful means of occluding something really rather worse. Mythologies was first published (in France) in 1957 and Barthes has a range of contemporary cultural works in mind - including From Here to Eternity's inoculating representation of the army as an institutionally brutal entity - but this trope is not a thing of the past as we can see from its use by the TV shows under consideration here. Life on Mars and Ashes to Ashes both inoculate the police not just by acknowledging the bigotry and violence of the Police but also by pushing it back into the past; leaving our 'now' cleansed of this little evil. This double inoculation is also found in George Gently where it is the bigotry and violence of the law that is treated to the ideology of now.
In both cases the inoculation, already a subtle ideological instrument, is doubled by the use of the past as a dumping ground of acknowledged evils. It is, therefore, worth making doubly sure we know what we are looking for. So let us finish with Barthes recapitulation of this trope from the final section (Myth Today) of Mythologies:
The inoculation. I have already given examples of this very general figure, which consists in admitting the accidental evil of a class-bound institution the better to conceal its principal evil. One immunizes the contents of the collective imagination by means of a small inoculation of acknowledged evil; one thus protects it against the risk of a generalized subversion. This liberal treatment would not have been possible only a hundred years ago. Then, the bourgeois Good did not compromise with anything, it was quite stiff. It has become much more supple since: the bourgeoisie no longer hesitates to acknowledge some localized subversions: the avant-garde, the irrational in childhood, etc. It now lives in a balanced economy: as in any sound joint-stock company, the smaller shares--in law but not in fact-- compensate the big ones.
P.S. for some other media tropes see here and for a good institutional reading of the current series of Ashes to Ashes see here (with some audience numbers here).