could be a surprise on sunday in part because the voting is mandatory for chiles 15 million voters its possible that polls are not able to truly understand voter intent said mario herrera a researcher at the political analysis centre at talca university a key issue is whether people believe they will truly be fined if they dont vote there may also be room for a surprise because of the unique time in chiles history over the last few years chile has found itself in a moment if refounding questioning the political and economic system and that hasnt changed funk said its probable that rejection will win but we cant rule out the possibility that approval will come out on top because campaigners have an emotional argument to get rid of the old document at the closing rally of the campaign to approve the new constitution on thursday night thousands of people took over a main santiago avenue they danced waved flags and chanted support amid widespread optimism they can prove the pollsters wrong there is a large group of people who will go vote who normally dont natalia iriarte a school teacher said at the rally in explaining why she is optimistic about the prospects for the new document it wont be easy chile is a country that is very reticent to change