ON THE TOPIC OF IMMIGRATION, President Bush is finding it increasingly difficult to bridge the gap between two wings of his party: the business lobby and the social conservatives who want to close the border and clamp down on illegal immigration. But Bush persists in wanting to simultaneously placate those who want to legalize the flow of labor across the Rio Grande and those who want to end it.

So the same week saw the administration promising tougher border enforcement and pitching its guest worker program. On Tuesday, Bush signed a $30.8-billion domestic security bill that includes money to hire new Border Patrol agents, improve border technology and intelligence capabilities and build more Border Patrol stations and better fencing. To please the business community and to appeal to moderate Republican legislators, the president reiterated his support for a guest worker program that would allow illegal immigrants, some already working here, to obtain a working permit for as long as six years before returning home.

The two approaches are not incompatible. What makes no sense, however, is the insistence by conservative House Republicans, expressed in a recent letter to Bush, that no action be taken on a guest worker program until border crossings and current laws are more effectively enforced. The logic here is flawed; current immigration laws are too divorced from economic reality to be enforceable. Washington now sets an unrealistically low cap on legal visas, forcing U.S. businesses to rely on a black market for labor.

It would be far better for the United States to legally seek the workers it needs to import in a given year and to free resources to police the border against real threats, such as terrorism.

That was the message delivered by Labor Secretary Elaine L. Chao and Homeland Security Secretary Michael Chertoff at a Senate Judiciary Committee the same day the president addressed immigration. They fleshed out some of the mechanics of a possible guest worker program. Foreign workers, here or abroad, could apply for a one-time, renewable three-year visa if matched with an employer. Illegal immigrants already working in the United States would be fined before entering the program. And a biometric identification card would allow Homeland Security to track his or her whereabouts.

Since 2001, immigration reform has been repeatedly bumped off the president's list of priorities, ostensibly because there is always something more urgent. But it is starting to seem like the delay may also have to do with the political difficulty involved. Bush doesn't want to antagonize either wing of his party, so he keeps flirting with both on immigration.

That's unfortunate. There are enough Democrats, moderate Republicans and even conservative border state Republicans in Congress who understand what needs to be done — and the high cost of not doing it. Bush should lead them in bringing our nation's immigration laws closer in line with reality.