Jeff Jacoby: “For any large political party, a boisterous battle over policy and principle is a sign of fitness, not feebleness. While ‘diversity’ is a sacred cow on the left, it is on the right where real diversity – diversity of ideas and viewpoints – has most often been showcased. In the 1970s, Ronald Reagan famously debated William F. Buckley Jr. on whether the United States should relinquish the Panama Canal. In the 1980s, Bob Dole and Newt Gingrich fiercely clashed over supply-side tax cuts. More recently, Republicans have gone at each other over war in Iraq, education reform, and ‘enhanced interrogation.’ However disconcerting in the short run, the right’s current rumble over immigration policy is heartening, especially when the argument focuses on ideals and values, and reflects a thoughtful interest in crafting wise, not merely popular, public policy. … It’s true: Republicans and others on the right, battling it out over immigration, seem awfully fractious and confused these days. For those who take their ideas seriously, that’s often how the democratic process works.”