"In 1971, the Middle Class Accounted for 61% of the Population, and It Has Been Declining Steadily Since"

"Many analysts and policymakers regard the shift as worrisome for economic and social stability. Middle-income households have been the bedrock of consumer spending, and many liberals in particular view the declining middle as part of a troubling trend of skewed income gains among the nation's richest families.
"Median-income voters, particularly non-college-educated men, are also at the core of billionaire Donald Trump's surprising surge in the Republican presidential campaign. His supporters' sense that their once-secure middle-class standing is in danger of slipping appears to be fueling much of the anger against the government and immigrant groups."

Don Lee in the Los Angeles Times reports that the middle class is no longer the majority in the United States.