1. Economy "The failure of the economy to deliver real progress to middle-class and working-class Americans over the past 15 years is the most fundamental source of public anger and disaffection in the US," says William Galston, an expert in governance studies at the Brookings Institution think tank. Although the country may have recovered from the recession - economic output has rebounded and unemployment rates have fallen from 10% in 2009 to 5% in 2015 - Americans are still feeling the pinch in their wallets. Household incomes have, generally speaking, been stagnant for 15 years. In 2014, the median household income was $53,657, according to the US Census Bureau - compared with $57,357 in 2007 and $57,843 in 1999 (adjusted for inflation). There is also a sense that many jobs are of lower quality and opportunity is dwindling, says Galston. "The search for explanations can very quickly degenerate into the identification of villains in American politics. On the left, it is the billionaires, the banks, and Wall Street. On the right it is immigrants, other countries taking advantage of us and the international economy – they are two sides of the same political coin." 2. Immigration America's demographics are changing - nearly 59 million immigrants have arrived in the US since 1965, not all of whom entered the country legally. Forty years ago, 84% of the American population was made up of non-Hispanic white people - by last year the figure was 62%, according to Pew Research. It projects this trend will continue, and by 2055 nonHispanic white people will make up less than half the population. Pew expects them to account for only 46% of the population by 2065. By 2055, more Asians than any other ethnic group are expected to move to the US. "It's been an era of huge demographic, racial, cultural, religious and generational change,"says Paul Taylor, author of The Next America. "While some celebrate these changes, others them. Some older, whiter voters do not recognize the country they grew up in.There is a sense of alien tribes," he says. The US currently has 11.3 million illegal immigrants. Migrants often become a target of anger, says Roberto Suro, an immigration expert at the University of Southern California. "There is a displacement of anxiety and they become the face of larger sources of tensions,such as terrorism, jobs, and dissatisfaction. We saw that very clearly when Donald Trump switched from