Politicians often boast that this is a nation of immigrants. But not all want more of them. Sometime this month, perhaps this week, Australia’s population will hit 25m. Its astounding growth is driven mostly by immigration, and the conservative coalition government is divided over where to stop. Net overseas migration (immigrants minus departing Aussies) has risen nearly 60% since 2000. By mid-century there will be 36m people in Australia. That is good for the economy, which is enjoying its 27th year of recession-free growth. Immigrants provided labour during a recent mining boom. When it ended, their demand for housing and education averted a bust. The problem is that most congregate in Sydney and Melbourne, where house prices have soared and roads are clogged. Tub-thumping politicians clamour for cuts. Yet Australians are growing more accepting. Surveys suggest they were more likely to believe that immigration was too high in the 1990s than they are today.