WASHINGTON -- This week in a speech to border and customs agents in Tucson, Ariz., President George W. Bush fastened the nation's attention on our immigration imbroglio. That should come as no surprise. Many Americans are very concerned about immigration policy. Nation of immigrants that we are, our appraisal of the problem has changed -- once again.

 During periods of the 19th century the nation was ambivalent about immigration. A whole political party, the Know-Nothings, was against it in the 1850s. Toward the end of the century, when large groups of Irish and Italians were swarming in, the nation's older immigrants were against it. Yet, as the 20th century took on years and the economy became more industrialized and prosperous, Americans viewed immigration more benignly. A majority came to a positive acceptance of it.

 That is not true today. Certainly it is not true with regard to illegal immigration. For the first time since the Gallup Poll began, a majority of Americans think immigration is bad rather than good. Thus politicians of all persuasions are promising action. The Bush policy is to address border security and illegal immigration. The president has reversed his emphasis. Last time around he suggested addressing illegal immigration first with a guest-worker program, and tough enforcement of border control second. Those in favor of tough enforcement of border control and of action against illegal immigration think the President is not being tough enough, and these "restrictions" are drawn from both ends of the political spectrum.

 Both sides in this debate fail to note the obvious. There is a market for immigrants in this country. The president is more cognizant of this than those who would restrict immigration, but turn to consider the market for a minute: 1) producers need immigrants; 2) immigrants are coming here because there is work that enriches them. This market has been helpful to the economy. It is growing robustly and without one of the feared downsides of immigration or even illegal immigration, unemployment. We are almost at full employment, and with two to three times as many illegal immigrants in the country as in the mid-1980s, when Sen. Alan Simpson last addressed the immigration issue, that is pretty much proof that the economy can accept immigration and prosper.

 The real problem is border security and an orderly society. We need to know who is entering the country and that they abide by the laws. So Congress is preparing a series of get-tough measures. The toughest of which is probably that envisaged by Tom Tancredo of Colorado and J.D. Hayworth of Arizona. Their legislation would deputize state and local police to arrest the millions of illegal immigrants (possibly 12 million) and deport them. Some argue we should somehow drop the arrested immigrants into the interior of their countries. How would this be done, by a gigantic parachute drop?

 Any prudent law has to be based on what James Madison in "The Federalist Papers" called the "genius" of the people. The American people are by nature generous, optimistic and tolerant. It is apparent, at least to me, that as we began arresting illegal immigrants the process would soon come to a sorry end. Wretched immigrants would be held up by many Americans now favoring the tough approach as the victims of unjust law enforcers. Civil libertarians would step in. The approach would be brought to ruin, and the "hate-America" crowd would have more spurious evidence that this is a racist and intolerant country. There is a better approach.

 We have the capacity to close off the border and we should. We also have the capacity to encourage many of the illegal immigrants to enroll in a program aimed at amnesty, but one that does not make chumps of legal immigrants who have played by the rules. The legislation of the 1980s ended in amnesty and well over half the illegals became law-abiding citizens. The burden on the president and Congress is to close off the border and get the present immigrants to enter amnesty programs.

 This is not an easy thing to accomplish, but it is certainly more practical and feasible than the "tough" approaches now being bandied about. The market for immigrants is here and will not evaporate. The Know-Nothings faded away but the bad repute they settled on the country endured -- unfairly, but it endured.