I interpreted his comment that crime is not a matter of double-entry bookkeeping as such that the act of behaving in a matter which undermines the fabric of civil/moral society is not canceled by the completion of a civil penalty.
Much like the idea that it tends to be easier to destroy things than to create things, the energy spent to frustrate the moral good is much less than the energy of goodwill and understanding required to repair it.
As an extreme example, I would say that the damage a criminal does to a victim of rape does not go away when he’s released from prison after serving his sentence. The damage to the victim, loved ones, and to society in general lasts and those ripples extend outward. I don’t think society really recovers in that case.
Toward the end of the article he talks about the liberal establishment and how they have been promoting and perpetuating evil. We all have seen what’s been going on in our country. For decades the Margaret Sangers, Bill Ayres, Rev. Wrights, NEAs, liberals and many others have been spending vasts amounts of energy to degrade the institutions which bolster and support the moral fabric of the USA.
We can do our best to raise families and preserve/fight for institutions which counter their efforts, but at some point just pushing back may not be enough.
There are less victims and ripples as long as a perpetrator is incarcerated, thus the 'reduced cost'.