Populists and Democracy

If you switch on the news you will hear politicians like Trump and Hofer in Austria being labelled as "populists". The newsreader clearly thinks that this is a derogatory term but is it?
Aren't politicians there to represent the population? Can you blame the politician for presenting policies that many of the electorate support?
Is this a snobbish term used by the elite for politicians who represent lower classes?
Is democracy even a good idea when so many people seem to support such unpalatable policies?