americans are being radicalized by violent extremists at a rate that is straining law enforcement's ability to stop suspects before it's too late. >> pelley: jeff pegues in our washington newsroom. jeff, thanks. in a related story, there was a rare victory today for supporters of tougher gun laws. the united states supreme court let stand a local law in illinois that bans semi- automatic weapons and large- capacity magazines. jan crawford is following this. >> reporter: the justices gave no reason for why they turned down the challenge to the ban on assault weapons in an illinois town. but in dissents, justin clarence thomas, joined by justice antonin scalia, said lower-court rulings upholding the bands were