Many US cities are near bankrupt and probably a lot more will be in the next ten years. There will be enormous political pressure to cut costs. One way to cut costs is to reduce pensions or fail to fulfill pension promises. I don't advocate this and in fact I think the police are being setup in some ways. By allowing some police to engage in what looks like theft the general public will be amenable to pension cuts in the future.

Just see Detroit as an example of our possible future.

I've never seen police unions on the chopping block. After the most recent crisis, teacher unions and other government worker unions were paraded around as needing to be fixed.