By failing to separate from far-right extremists, rally organisers may have undermined their own cause and genuine anti-immigration concerns, writes Dr Peter Cook. Yet did the "success" of these marches damage the broader cause of public discussion about the impacts of population growth on environment, housing and infrastructure? Polarising the debate in this way ignores the vast majority of Australians (repeated polls show 70 per cent) who oppose further population growth. Many across the political spectrum are seeing the damaging impacts of high population growth on economy, environment and, yes social cohesion as well. Dr Peter Cook, PhD, is vice-president of Sustainable Population Australia (SPA) and joint author of the SPA discussion papers, Population and climate change (2022) and Big thirsty Australia: How population growth threatens our water security and sustainability (2024).