SENATORS JOHN MCCAIN AND JON Kyl, both Arizona Republicans, have an unstated agreement not to criticize each other in public. But now each has introduced legislation to reform the immigration system. The two bills are competing head to head. And when the two men appeared together last month at a Senate hearing, McCain could not resist.

It "borders on fantasy," he said scathingly, to expect the estimated 11 million illegal immigrants in the United States to sign up for a guest worker program that would compel them to leave the country, as the bill introduced in July by Senators Kyl and John Cornyn would require. "'Report to deport,'" McCain went on, using dismissive slang for the Cornyn-Kyl provision, "is not a reality and it isn't workable."

By the standards of the Senate, it was a blunt, angry exchange, and there will surely be more like it in the months to come as Congress wrestles with these two proposals on one of the most controversial issues facing the nation. Still, despite the fireworks--and even with politicians as diverse as President Bush, House Speaker Dennis Hastert, and Senators Kyl, Cornyn, McCain, and Edward Kennedy weighing in--there is much more consensus on immigration than is generally recognized.

We're not quite at the point yet where, as is said about the Israeli-Palestinian problem, "everyone knows what the solution is--the only difficulty is getting there." But there is increasing agreement about the contours of the problem and even about critical elements of the solution.

The emerging consensus starts with a

Gone are the days when one side in the debate was concerned about immigrants and the other about angry native-born voters--when one side wanted expansive annual quotas and the other wanted tighter control over the system. Today, reformers as different as Kyl and Kennedy (cosponsor of the McCain legislation) recognize that robust immigration is a boon to the U.S. economy, but that we must construct a system--a more regulated, orderly system--that permits foreign workers to enter the country in a lawful manner. Both sides recognize that we need immigrants and the rule of law--that we need foreign workers, but also control. The war on terrorism demands this better control, and so, increasingly, does the public. From the Minutemen volunteers on the Arizona border to angry suburbanites in Herndon, Virginia, and on Long Island, voters are expressing frustration, and lawmakers in both parties know they must respond.

Second, and even more encouraging, politicians as far apart as the president and Senator Kennedy grasp the paradoxical nature of the remedy: namely, that the best way to deliver control is not, as many reflexively think, to crack down harder, but rather to expand the channels through which immigrant workers can enter the country legally. This consensus is reflected in the competing bills in the Senate, and it is at the heart of the White House's position (a position reiterated in recent weeks in a series of private meetings with legislators). All of the current reform proposals rest on two central pillars: a guest worker program and much tougher enforcement.