Help me identify this film

A long time ago, I saw a film about a young Jewish man who for some bizarre reason joined up with a gang of racist skinheads. Among other things, he went into a Jewish delicatessen with his skinhead buddies and harassed the waiter for refusing to put cheese on a roast beef sandwich.* Leaders in the white power movement began grooming him for a leadership spot in the movement.He gets involved in a bomb plot, and the film ends with him endlessly running up the same flight stairs over and over again trying to stop the bomb from going off.

Has anybody else seen this film? Can anybody tell me the title?

*Which apparently isn’t kosher, but what do I know about kosher?

Is it The Believer?

Yes! That’s it! Thank you so very much!