Given that the world is dominated by demon-serving (mostly-) human beings; it is likely that - in the spiritual war - even apparently-good policies are of evil intent; and may have net-evil outcomes.
Thus what looks like a demonic defeat may be turned into their partial victory.
As CS Lewis explains from the perspective of a devil in his Screwtape books; getting people damned is a difficult business, because ultimately they must want to be damned.
Expressing evil ideas, doing evil acts is insufficient - the demons need to ensure that these are not repented.
In other words; people must think or do something evil, and then double-down on it.
This may be the correct interpretation of those rare, 'good', public policies that are approved by Christians.
Such policies probably do not make a difference to those who are already on the side of God. And their effect on the undecided could go either way.
But the primary demonic intent in such cases is probably to ensure that those who oppose good policies, become active in their opposition to good - that they convince themselves that evil is actually good.
For instance; the recent US change to abortion rules does not affect Christian attitudes; but seems to have led to a highly-significant doubling-down on pro-abortion attitudes; to the point that abortion is apparently seen (by more people than ever, more strongly than ever) as a core moral principle; a positive, desirable thing that ought to be encouraged and facilitated in every possible way.
Such is the nature of public discourse in these end times: specific good may be turned to encourage overall evil outcomes. This does not mean that we should resist good policies; but it does mean that Christians need to discern the intent and effect such policies actually-have (and are meant to have) on those already affiliated to evil. And adjust our public responses accordingly.