This discusses it.
http://en.wikipedia.org/wiki/Strict_scrutiny
It is similar in nature to proof in a court by the trier of fact, mostly juries, but can be a bench trial; (Civil) Preponderance of the evidence; Clear and convincing evidence; (criminal) Beyond a reasonable doubt.
If it does not survive "scrutiny", no matter what kind, see the link, the court will strike it down.

