Reasons For Enumerating Constitutional Rights, Pt. Whatever

Roger Ailes (not that Roger Ailes) brings word of the following:

The writer David Irving was arrested in Austria last week, according to a statement on his Web site. Although he has not yet been charged, he is suspected of the crime of Holocaust denial.

Okay, for those not familiar, David Irving is a Holocaust denier. But let's repeat: Irving was arrested for the crime of Holocaust denial. Thoughts, Tom? If Congress enacted a ban on Holocaust denial that included a substantive finding that preventing public dissemination of Holocaust skepticism was a sufficient good to infringe on freedom of speech, on what grounds, if any, could a court overturn such legislation?