Hughes amendment controversy

[Numenor]

I hadn't realized there was so much controversy regarding the Hughes amendment to the FOPA; that the machine gun ban is potentially illegal.

Here's a couple interesting links:

Link Removed
-- the actual transcript with link further down to the archived footage

Machine Guns WEREN'T Banned? in [Market-Ticker]
-- another page with the footage

So now... assuming this is correct, why the HELL hasn't it been challenged in court yet?!