Don't listen to Teddy Kennedy. If you belong to the small band of conservative brothers inclined to support immigration reform, the Massachusetts senator is on your side. But what he says is likely to make you anxious, vexed, or even crazed. At times, Kennedy makes the compromise immigration bill sound like the latest loopy liberal legislation to provide welfare to the world.

It's not. Indeed, much of the organized left opposes it. The AFL-CIO is especially upset about the provision to bring foreign workers here temporarily. But when you hear Kennedy on the subject, you have to wonder what they're so worried about.

The temps, Kennedy insisted last week, are "going to get the prevailing wage, they are going to be protected by OSHA, if they get hurt on the job they are going to get workmen's compensation. They are going to get worker protections. If they are working on a construction site, they are going to be covered by Davis-Bacon."

Kennedy contrasted this pampering with the fate of those poor illegal immigrants who work here now. Absent the new program, Kennedy said, they'll continue to be exploited, their rights "trampled on." They'll be injured by "sharp hooks, knives, exhausting assembly line speeds." In Massachusetts, illegal workers are "fired for going to the bathroom, denied overtime pay, docked 15 minutes' pay for every minute they were late . . . fired for talking while on the clock, forced to ration toilet paper."

As Senate floor manager of the immigration bill, Kennedy gets emotionally wound up. He exaggerates. He raises his voice. He berates Democratic and Republican senators alike. He intimidates, or tries to anyway. He is a throwback to an older oratorical style. He is a bellower, a bully, something of a blowhard. He is enormously fun to watch.

But what's important about Kennedy is that he's the ally of pro-immigrant Republicans in the Senate debate on the bipartisan immigration bill. And Kennedy is effective. The Republicans gave up a lot to get Kennedy, particularly in agreeing to "Z" visas that would allow the estimated 12 million illegal immigrants already in the United States to stay as legal residents and eventually seek citizenship.

Led by conservative Jon Kyl of Arizona, the Republicans gained Kennedy's support for three significant provisions. The first is a buildup of border security that must be completed before Z visas can be issued and other reforms implemented. The second is a temporary worker program in which the workers must return to their home country. In this bill, Kyl says, "temporary means temporary." And the third is the end of "chain migration," the practice that has allowed legal immigrants to bring their endless extended families here. If the compromise becomes law, only the immigrant, spouse, and minor children will be allowed in.

Should any of these provisions be stripped from the bill, the compromise will fall apart and immigration reform will die, for the foreseeable future anyway. And Kennedy may be the only person who can stop liberal Democrats from stripping and thus killing the bill. He's succeeded so far, and it now appears the bill will pass the Senate when debate resumes in June. The House, where there's no Kennedy counterpart, is another matter.

Kennedy single-handedly turned back an effort by Democratic senator Byron Dorgan of North Dakota to wipe out or limit the temp program. Dorgan initially proposed to strike the program entirely. Kennedy's response was ferocious. He referred to Dorgan as the "senator from North Carolina." He said, contrary to what Dorgan had argued, that illegal immigrants, not legal temps, drive down wages.

"I would like the chicken-pluckers to pay $10 or $15 an hour," he said. Today, when they hire illegal immigrants, "they do not do it." He roared at Dorgan, "Who are you trying to kid? Who is the senator . . . trying to fool?"

Dorgan later proposed to end the program after five years, another compromise-killer. This would alienate the business lobby, which supports the bill largely because of the temp program. Dorgan had the votes to win, 49-48, until Kennedy intervened at the last moment. He persuaded Democrat Daniel Akaka of Hawaii to change his vote, and Dorgan lost, 49-48. And the bill was saved.