The only way to do that, sad to say, is for the Supremes to kill it AFTER it has been made law.
That doesn't stop Congress from passing it again either, as they did with the gun free school zones business. The SC told them schools were not commerce, let alone interstate commerce, but they just added a little more interstate commerce pixie dust in the "findings" and passed it again. They'll do the same with this. In fact in some sense this is passing something again after the Courts found the previous incarnation, with some of the same provisions, unconsitutional. Not as blatent as with the unarmed victims zone thing, but no different in principal.
You really think they would repeat this bill ? They would raise the hard money limits even higher in trade for a ban that gets shot down by the SC ? Also, you don't think the liberal Rats don't have some splaining to do with their own base when they wake up to the fact thier own voices are silenced ?