Since its inception in the mid-2000s, the Five Star Movement (M5S) has represented itself as a vehicle for alternative voices in Italian politics — and a departure from the corruption and complacency of mainstream parties. Unrefined and unconventional, M5S began as a quasi-protest movement that coalesced around comedian and blogger Beppe Grillo. His against-the-grain attitude and promises of “cleaning up parliament” resonated with many Italians’ deep frustration with the political establishment — attracting a constellation of fringe and outsider beliefs toward M5S.

After registering as a party in 2009, M5S initially upheld founding principles such as bottom-up leadership and direct democracy. Its candidates were drawn from grassroots networks and its policy guided by its members voting on an online platform named “Rousseau” — a nod to Swiss philosopher Jean-Jacques Rousseau’s ideas of the social contract and ordinary people’s natural virtue.

But today, M5S is leading a coalition of major parties supporting the “Yes” camp in a vote which threatens to drastically reduce the breadth and diversity of Italy’s political landscape. If the “Yes” side wins the September 20–21 constitutional referendum, as expected, this will mean slashing over one-third of the seats from Italy’s national parliament.