He's stating a simple, undisputable fact about the past 20+ years in America.
Yes they are disputable. Overall real income (measured in constant dollars) went up about 10% between 1980 and 2004. Median income for African Americans increased about 30% in the time span. Real income for women increased 65%.
I went back to school in 1982. Initially my income dropped after graduation because I was going to entry level jobs in a new field. Between 1985 and 2005 my real income went up about 300%. In the smaller entrepenurial companies I was working in, everybody with some smarts and willing to work hard got ahead. These types of companies are going to get hit hard by Democratic party tax proposals.