In What is Populism?, Jan-Werner Müller provides a timely perspective on the pressing question of what populism is and how to respond to it. Defining populism as anti-pluralist, elite-critical politics with a moral claim to representation, he cautions that populists are both willing and able to govern and may therefore deform democracy by turning states towards partisanship. This short book is a recommended read for academics as well as the wider public, writes Theresa Gessler