ALIEN NATION.(The Talk of the Town)(immigration)

In a jaded and stage-managed political culture, it is rare to see the eruption of a genuine popular movement. That's what happened in Los Angeles the other week, when hundreds of thousands of people protested against congressional efforts to crack down on illegal aliens. The marchers, most of them Hispanic, set out from the intersection of Olympic Boulevard and Broadway. By the time the stragglers reached City Hall, California had witnessed the biggest demonstration in its history.

Even more stunning was the sound of a once marginalized community finding its voice. For years, the immigration debate has been exercising politicians, economists, TV pundits, and editorial writers, not to mention the self-styled militia known as the Minutemen, which patrols the southern border. Here, finally, were the janitors, maids, dishwashers, babysitters, garment workers, office cleaners, shelf-stackers, busboys, cooks, gardeners, pool boys, and fruit pickers who do the work that American citizens generally won't do--at least, not at the wages being offered. Shedding their customary aversion to publicity, the immigrants lambasted the House of Representatives for approving a bill at the end of last year that would make living in the United States without a visa an "aggravated felony," impose heavy fines on firms that employ illegal aliens, and order the Department of Homeland Security to build a tall fence along sections of the Mexican border.

News of the demonstration spread across the world. Many commentators were heartened by the spectacle; an Irish newspaper saw "the face of a joyously multicultural America." Not everyone shared that view. On Fox News, Bill O'Reilly accused the demonstrators of intimidation. On talk radio, angry callers claimed that the marchers were "anti-American," citing the profusion of foreign flags and Spanish-language placards. In fact, many marchers were carrying American flags, some of which were emblazoned with pictures of family members serving in the United States military. (For young immigrants, the surest way to secure American citizenship is often to join the armed forces.) Other marchers brandished signs that said, "We love USA, too."

A few days after the L.A. protest, which followed similar events in Chicago, Miami, and other cities, the Senate Judiciary Committee approved a proposal that was much friendlier to illegal aliens than the House version. The new measure would give illegal workers the opportunity to apply for work visas, green cards, and, eventually, American citizenship. It also would create an expanded guest-worker program, allowing four hundred thousand more people a year to enter the United States legally. (Under the current system, about eight hundred thousand immigrants arrive here legally every year; another half million or so arrive illegally.) Although the new Judiciary Committee proposal has the tacit support of the White House, Senate Republicans remain split. Six Republicans on the Judiciary Committee voted against the proposal. In the full Senate, and in the House-Senate conference, which will attempt to reconcile the House and Senate bills, the proposal will encounter conservatives who favor a battendown-the-hatches policy.

For some Republicans, especially those facing midterm elections in predominantly white districts, acting tough on immigration has certain diversionary advantages. "Would I rather be talking about immigration reform with these voters or the war?" the Republican pollster Tony Fabrizio said to Ruth Marcus, of the Washington Post. "Immigration reform or gasoline prices?" Other immigration hawks have more substantive points to make. At a time when the federal government is spending hundreds of billions of dollars on the war on terror, it hardly makes sense to have such porous borders.

There are also legitimate questions about the economic impact of illegal immigration. Academic ...