at Nctu jjork C.rAmcs October 23, 2012 Standard of Living Is in the Shadows as Election Issue By DAVID LEONHARDT WASHINGTON — Taxes and government spending. Health care. Immigration. Financial regulation. They are the issues that have dominated the political debate in recent years and have played a prominent role in this presidential campaign. But in many ways they have obscured what is arguably the nation's biggest challenge: breaking out of a decade of income stagnation that has afflicted the middle class and the poor and exacerbated inequality. Many of the bedrock assumptions of American culture — about work, progress, fairness and optimism — are being shaken as successive generations worry about the prospect of declining living standards. No question, perhaps, is more central to the country's global standing than whether the economy will perform better on that score in the future than it has in the recent past. The question has helped create a volatile period in American politics, with Democrats gaining large victories in 2006 and 2008, only to have Republicans return the favor in 2010. This year, economic anxiety, especially in industrial battlegrounds like Ohio, is driving the campaign strategies of both President Obama and Mitt Romney. The causes of income stagnation are varied and lack the political simplicity of calls to bring down the deficit or avert another Wall Street meltdown. They cannot be quickly remedied through legislation from Washington. The biggest causes, according to interviews with economists over the last several months, are not the issues that dominate the political debate. At the top of the list are the digital revolution, which has allowed machines to replace many forms of human labor, and the modern wave of globalization, which has allowed millions of low-wage workers around the world to begin competing with Americans. Not much further down the list is education, probably the country's most diffuse, localized a