Cheap Chinese goods have benefited American consumers and restrained inflation. But those imports have hurt American manufacturers. And many U.S. companies outsource production to China. One study estimated that between 2001 and 2010, 2.8 million U.S. jobs were lost or displaced to China.
What, exactly, is discrimination, and what should be done to fight it? This election offers choices on the answer.
In areas such as mortgages, voter identification and immigration enforcement, the presidential candidates differ over how to use laws that guarantee equality and how far the Justice Department's civil rights division should go to ensure all Americans are treated fairly.
The election also will shape the Justice Department's actions in continuing court cases that challenge voter ID laws passed in some Republican-led states. Opponents contend such laws unfairly discourage minority voting.
Under Obama, the government has aggressively prosecuted cases where statistics show that blacks and Hispanics are hit harder than whites. Under recent Republican presidents, the Justice Department has limited its enforcement to cases with evidence of intentional discrimination — not where statistics show that minorities were broadly disadvantaged by a particular practice.
This year America's weather has been hotter and more extreme than ever before, records show. Yet the presidential candidates aren't talking about it.
In the U.S. July was the hottest month ever recorded, and this year is on track to be the warmest. Scientists say that's both from natural drought and man-made global warming. Each decade since the 1970s has been nearly one-third of a degree warmer than the previous one.
Sea levels are rising while glaciers and summer Arctic sea ice are shrinking. Plants are blooming earlier. Some species could die because of global warming.
Obama proposed a bill to cap power plant carbon dioxide emissions, but it died in Congress. Still, he's doubling auto mileage standards and put billions into cleaner energy. Romney now questions the science of man-made global warming and says some actions to curb emissions could hurt an already struggling economy.
The risk of a devastating cyberattack on the United States is real. Yet the country remains vulnerable to an electronic Pearl Harbor due to a political dispute over the role the federal government should play in securing the computer networks that control the electrical grid, water supply and other critical sectors.
Obama wants the owners of essential U.S. infrastructure to meet minimum cybersecurity standards. But Republicans in Congress say the president's approach will only lead to costly, time-consuming regulations that won't reduce the risk. Romney says Obama has failed to lead on a critical national security issue.
While Congress bickers, the Pentagon worries. "The uncomfortable reality of our world today is that bits and bytes can be as threatening as bullets and bombs," Gen. Martin Dempsey, the chairman of the Joint Chiefs of Staff, told lawmakers.
A sea of red ink is confronting the nation and presidents to come.
The budget deficit — the shortfall created when the government spends more in a given year than it collects — has topped $1 trillion for a fourth straight year. The government borrows about 31 cents for every dollar it spends.
The national debt is the total amount the federal government owes. It's risen to a shade over $16 trillion.
Obama has proposed bringing deficits down by slowing spending gradually, to avoid suddenly tipping the economy back into recession. He'd raise taxes on households earning more than $250,000 and impose a surcharge of 30 percent on those making more than $1 million. Romney would lower deficits mostly through deep spending cuts. But many of the cuts he's pushing would be partially negated by his proposals to lower top tax rates on corporations and individuals.