IT WAS HARD TO TELL from the headlines and instant controversy, but President Bush's January 7 immigration speech was not about granting amnesty to illegal aliens. Instead, the president has proposed a measure that would dramatically curtail illegal immigration. However, to the consternation of critics, he favors a method--temporary worker visas--that anti-immigration members of Congress and their allies despise.

Under President Bush's plan, immigrant workers would no longer need to evade Border Patrol agents or die trying. Moreover, recognizing reality, the president would allow those now working illegally in this country to pay a fine and obtain a temporary visa, good for three years but renewable. Crucially, the president recognizes that "our current limits on legal immigration are too low," and he pledged to work with Congress "to increase the annual number of green cards."

A little background helps explain why this last point is so important. Contrary to some perceptions, current law is in practice highly restrictive in offering opportunities for U.S. employers to hire immigrants to work legally in agriculture and other non-professional fields. While H-2A visas for agricultural workers are uncapped, the procedure for obtaining them is so cumbersome and litigation-prone that fewer than 30,000 such visas are issued annually, while several hundred thousand immigrants work in the fields illegally. Though individuals may work in non-agricultural jobs under the H-2B visa, restrictive interpretations of the statute have generally prevented employers from hiring individuals for jobs other than those that are seasonal or of very short duration. In addition, that

The absence of avenues to work legally in the United States is a primary reason for the current levels of illegal immigration. This can be seen clearly by looking back at the bracero program, which allowed foreign agricultural workers easier access to U.S. jobs.

As the bracero program expanded in the 1950s, INS apprehensions of illegal immigrants fell from the 1953 level of 885,587 to as low as 45,336 in 1959--a 95 percent reduction in the flow of illegal immigration into the United States. From 1964--when the bracero program ended--to 1976, INS apprehensions increased from 86,597 to 875,915 (and have remained at roughly that level or higher ever since).

This is not to say that workers who entered the bracero program did not experience problems or even hardships. The point is that when legal entry to work was widely permitted, illegal entry to the United States was an order of magnitude lower. And immigration enforcement officials understood this. At a congressional hearing in the 1950s, a top INS official was asked about stopping illegal immigration if Mexican agricultural workers could no longer come in legally. He replied, "We can't do the impossible, Mr. Congressman."

Congress can certainly choose to maintain the status quo, which is an enforcement-only approach. However, the evidence is strong that current policies--or even more hardened versions of them--are ineffective. From 1990 to 2000, illegal immigration increased by 5.5 million as the number of U.S. Border Patrol agents rose from 3,600 to nearly 10,000.