Mr. Bush might have thought he was answering lawmakers' pleas for help when he informed an audience in California that mass deportations wouldn't work. That's a sensible -- if fairly obvious -- generality. But this is a moment for specifics. The president could have argued forcefully for comprehensive reform and spelled out the distinction that the Senate has drawn between an earned route to legalization and the detested free ride of amnesty. Instead, he blandly labeled the Senate compromise an ''interesting approach,'' as if he were pondering a piece of modern art rather than the fate of something central to his domestic agenda.