Diane Ravitch Historian of education, NYU and Brookings :
Populism is a term with a complex and not altogether wholesome legacy. At one level, it refers to representing the interests of ordinary people. But it has also been used to refer to pandering to the base instincts of the mob. Tom Watson of Georgia was a leader of the Populist party in the early 20th century, who is now remembered most for his virulent appeals to racism and anti-Semitism. So I guess you might say that populism is in the eye of the beholder--either an idealistic rejection of the powerful, or a crass effort to exploit popular prejudice for personal or political gain.