Southern Arizona is a beautiful land of sage and mesquite, red rocks and rolling desert plains. It is a place of opportunity and disgrace. Each night the bushes rattle and the trails are worn down by thousands of mostly Mexican migrants who trudge sometimes for days to find gainful employment in the United States. These are sons and daughters, mothers and fathers, babies cradled in arms. Some are caught by border agents and returned. Most make it through, struggling with dehydration and exhaustion. More than 100 die every year.

Anyone who has traveled to Arizona to watch this migration is struck by two things. The border is enormous, far vaster than it appears on a grade school map. It may be possible to build an impenetrable wall, or moat, or mine field to guard the whole thing, but the project would cost untold hundreds of billions of dollars and probably require decades. Take out the Arizona border, and people will cross through Texas. Take out Texas, and boats will start landing on San Diego and Galveston beaches. More will die.

The second thing you notice is that the American immigration system is an utter failure. By and large, the people who cross the desert are coming to America because our legitimate employers want them to pick fields, build houses and work in factories. It is a blight on America that we force law-abiding people to suffer to serve us. The system is also a failure because it mocks the law. The nation’s businesses want the migrants here, but we still call them illegal.

For years, Congress has been struggling to find a comprehensive solution to this problem that would deal with all sides of illegal immigration: Increase border enforcement. Crack down on illegal hiring and phony Social Security cards. Find a path to legalization for those who are here illegally. Develop an orderly way for new immigrant labor to enter the country. For the most part, the leaders of both parties have agreed with President Bush on the principles of a solution. But so many Americans are so angry at the current state of affairs that politics has gotten in the way of good policy.

Now we are entering a highly contested presidential election season and rhetoric is set to increase. Michael Shear (no relation) has a fine piece in today’s Washington Post spotlighting all the contortions that the GOP presidential hopefuls are making around the immigration issue. John McCain, once a leader of the comprehensive reform movement, has begun to back away from the debate. But he is not alone. As Shear writes, “Former Massachusetts governor Mitt Romney, who just a year ago characterized the bipartisan efforts as ‘reasonable proposals,’ now derides the plans being negotiated in Congress as ‘amnesty’ for illegal immigration. Former New York mayor Rudolph W. Giuliani, whose record is filled with pro-immigrant speeches and actions, has been largely silent on the debate. And Sen. Sam Brownback of Kansas, another GOP contender, was a key McCain ally on immigration a year ago but recently renounced his support for the approach.”

The good news is that if any one of these men becomes president, he is likely to backtrack on the campaign rhetoric and return to a more rational approach to the problem. The bad news is that unless Congress gets its act together in the coming months, presidential politics will sink any hope for a short-term solution. The status quo will reign for many more years in the Arizona desert.