Think of America's greatest historical shames. Most have involved the singling out of groups of people for abuse. Name a distinguishing feature - skin color, religion, nationality, language - and it's likely that people here have suffered unjustly for it, either through the freelance hatred of citizens or as a matter of official government policy.

We are heading down this road again. The country needs to have a working immigration policy, one that corresponds to economic realities and is based on good sense and fairness. But it doesn't.

It has federal inertia and a rising immigrant tide, and a national mood of frustration and anxiety that is slipping, as it has so many times before, into hatred and fear. Hostility for illegal immigrants falls disproportionately on an entire population of people, documented or not, who speak Spanish and are working class or poor. By blinding the country to solutions, it has harmed us all.

The evidence can be seen in any state or town that has passed constitutionally dubious laws to deny undocumented immigrants the basics of living, like housing or the right to gather or to seek work. It's in hot lines for citizens to turn in neighbors. It's on talk radio and blogs. It's on the campaign trail, where candidates are pressed to disown moderate positions. And it can be heard nearly every night on CNN, in the nativist drumming of Lou Dobbs, for whom immigration is an obsessive cause.

In New York, Governor Eliot Spitzer has proposed allowing illegal immigrants to earn driver's licenses. It is a good, practical idea, designed to replace anonymous drivers with registered competent ones. In show after show, Dobbs has trained his biggest guns on Spitzer, branding him with puerile epithets like "spoiled, rich-kid brat" and depicting his policy as some sort of sanctuary program for the Sept. 11 hijackers. Someday there may be a calm debate, in Albany and nationally, about immigrant drivers. But with Dobbs at the megaphone, for now there is only histrionics and outrage.

Let's concede an indisputable point: People should not be in the country illegally. But forget about the border for a moment - let's talk about the 12 million who are already here. What should be done about them? Here are the choices:

A. Deport them all.

B. Find out who they are. Distinguish between criminals and people who just want to work. Get them on the books. Make them pay what they owe - not just the income, Social Security, sales and property taxes they already pay, but all their taxes, and a fine. Get a smooth legal flow of immigrants going, and then concentrate on catching and deporting bad people.

C. Catch the few you can, and harass and frighten the rest. Treat the entire group as a de facto class of criminals, and disrupt or shout down anyone or any plan seen as abetting their evildoing.

Forget A. Congress tried a version of B, but it was flattened by outrage. And so here we are at C. It's a policy that can't work; it's too small-bore, too petty, too narrow. And all the while it's not working, it can only lead to the festering of hate. Americans are a practical and generous people, with a tolerant streak a mile wide. But there is a combustible strain of nativism in this country, and it takes only a handful of match-tossers to ignite it.

The new demagogues are united in their zeal to uproot the illegal population. They do not discriminate between criminals and the much larger group of ambitious strivers. They champion misguided policies, like a mythically airtight border fence and a reckless campaign of home invasions. And they summon the worst of America's past by treating a hidden group of vulnerable people as an enemy to be hated and vanquished, not as part of a problem to be managed.