Online debate tools for participatory democracy and crowdsourcing legislation are limited by different factors. One of them arises when discussion of proposals reaches a large number of contributions and therefore citizens encounter difficulties in mapping the arguments that constitute the dialectical debate. To address this issue, we present a visualization tool that shows the discussion of any proposal as an interactive radial tree. The tool builds on Decide Madrid, a recently created platform for direct democracy launched by the City Council of Madrid. Decide Madrid is one of the most relevant platforms that allows citizens to propose, debate and prioritise city policies.