But the bill is all but dead in Congress, and there is little chance that even Bush can make it spring back to life.

As we have seen, the fight in Congress is bigger than the conservatives who want tougher border security and strict limits on immigration and liberals who want to create a pathway to citizenship for the 12 million unlawful immigrants already in the United States. Immigration has become the main wedge issue that splits the Republican Party.

On one side are the "movement" conservatives — the evangelicals, the anti-choicers and the gay-bashers who make up the core of the GOP's voters. Then there are the big money conservatives — the folks who write the checks, control the GOP and generally get whatever they want.

The movement folks hate illegal immigrants — they are enemies of "the other" — and want nothing to do with any politician who doesn't support border walls and deportation. The big money folks love the cheap labor that undocumented laborers provide and oppose tightening restrictions on immigration.

It is impossible to satisfy the desires of both of these groups, and the bitter fight that has resulted from the issue may ultimately tear the GOP apart.

It might be just as well that this bill going nowhere. It is overly complicated and fails to address one important fact — the key to reducing immigration is raising living standards in the countries that immigrants are fleeing.

Fifty-six percent of the unlawful immigrants in the United States are from Mexico. Why? There are jobs in this country, and there aren't enough in Mexico.

The Mexican economy has become so dependent on remittances from immigrant workers that they are now equal with oil revenues — they are the two largest sources of foreign income in Mexico. Mexicans sent $23.54 billion back home in 2006. According to figures from the Century Foundation, a think tank, for every dollar of foreign aid that goes to Mexico, immigrants send home $150.

The North American Free Trade Agreement, enacted in 1994, was supposed to improve Mexico's economy. Instead, it decimated it.

The inequities in trade policy have given U.S. corporations unfettered access to markets, resources and cheap labor in Mexico and the rest of Latin America. The results have been predictable.

For example, NAFTA has allowed American agribusinesses to flood Mexico with highly subsidized exports of American food and agricultural products. As a result, one-sixth of the Mexican agricultural workforce has been displaced over the past decade.

By depressing the economies of our neighbors, the United States has created a massive pool of unemployed immigrants who need jobs. Too many businesses in this country are benefiting from this. Unfortunately, it's the undocumented workers — not the people who employ them — who get punished.

As long as Mexico gets treated as a place for American corporations to plunder, Mexicans will do whatever it takes to cross the border and find a better life here. But the best immigration control measure might just be improving the economies of our neighbors so that their citizens will stay put.