Good Neighbor Policy By JORGE G. CASTAÑEDAPublished: May 4, 2006THERE are many excellent reasons to salvage the immigration bill that collapsed two months ago in the Senate. But one of the most overlooked lies not in the protests that have filled streets in Los Angeles and Washington, but in the wave of populism that has swept Latin American cities like Caracas, La Paz, Lima and Mexico City.An ultra-nationalist candidate, Ollanta Humala, seems poised to win a runoff this month in Peru’s presidential elections. He wants, among other things, to renationalize Peru’s natural resources, promote coca cultivation and align Peru against Washington with Venezuela’s Hugo Chávez and his Bolivian neighbor, Evo Morales (who on Monday sent soldiers to take control of Bolivia’s oil fields and refineries). Mr. Humala is part of Latin America’s new left turn — the wrong part of the left. Progressive leaders in countries with a long leftist history — Brazil, Chile and Uruguay — are economically moderate, ideologically tolerant and internationally open-minded. The other left — Mr. Chávez, Mr. Morales, Mr. Humala and Néstor Kirchner in Argentina — springs from a populist past and seeks a populist future: big-time spending, authoritarian governance and militant anti-Americanism.The great populist hope of that left is, of course, Mexico City’s former mayor, Andrés Manuel López Obrador, a strong contender in Mexico’s presidential race. By background and policies, he clearly belongs to the wrong left. Mr. López Obrador comes from the corrupt authoritarian machinery that governed Mexico for 70 years, just as Mr. Kirchner descends directly from Juan Perón, and Mr. Chávez and Mr. Humala began their political careers with failed military coups against corrupt but democratically elected governments. It is one thing to have populism in power in the Andes; it is quite another to have it controlling a 2,000-mile border with the United States. This is where leadership on immigration reform from George W. Bush and broad-minded Republican senators comes in.Nothing could contribute more to the continuity of sensible policies in Latin America than a clear signal from the north that cooperating with Washington, and renouncing America-bashing, pays off, even on an emotional issue like immigration. And few things could offer ultra-nationalist leaders better proof of America’s not-so-benign neglect and imperial arrogance as further paralysis on immigration.President Vicente Fox of Mexico staked much of his prestige on President Bush’s commitment to fix immigration policy. First Sept. 11 got in the way, then Iraq did; and so Mr. Bush left Mr. Fox empty-handed. But immigration reform along the lines of the Senate compromise would still give Mr. Fox a huge boost. It would strengthen support for Mexico’s policies of the last decade: economic stability and growth, democratic rule, a mature and responsible foreign policy and an innovative war on poverty. It would allow the United States to encourage that continuity, whoever wins Mexico’s July 2 elections, without interfering in its neighbor’s political process. Along with all the other good reasons for sensible immigration reform, this one is certainly worth acting on.